================================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13D
                    Under the Securities Exchange Act of 1934

                              (Amendment No. ____)

                                  BioTime Inc.
                                (Name of Issuer)

     Common Shares, no par value                         09066L105
   (Title of class of securities)                     (CUSIP number)

                            Gary K. Duberstein, Esq.
                                 Greenbelt Corp.
                           277 Park Avenue, 27th Floor
                     New York, New York 10017 (212) 350-5100

            (Name, address and telephone number of person authorized
                     to receive notices and communications)

                                 August 16, 1996
             (Date of event which requires filing of this statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(b)(3) or (4), check the following box [_].

Check the following box if a fee is being paid with the statement [x].

(A fee is not required only if the reporting person: (1) has a previous
statement on file reporting beneficial ownership of more than five percent of
the class of securities described in Item 1; and (2) has filed no amendment
subsequent thereto reporting beneficial ownership of five percent or less of
such class.) (See Rule 13d-7.)

Note: When filing this statement in paper format, six copies of this statement,
including exhibits, should be filed with the Commission. See Rule 13d-1(a) for
other parties to whom copies are to be sent.

                        (Continued on following page(s))

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- ---------------------------------           ------------------------------------
CUSIP No. 09066L105                  13D             Page 2 of 15 Pages
- ---------------------------------           ------------------------------------

- ------------------ -------------------------------------------------------------
        1          NAME OF REPORTING PERSON              GREENBELT CORP.  
                   S.S. OR I.R.S. IDENTIFICATION NO.     13-3791931
                   OF ABOVE PERSON

- ------------------ -------------------------------------------------------------
        2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:     (a) [x]
                                                                         (b) [_]
- ------------------ -------------------------------------------------------------
        3          SEC USE ONLY
- ------------------ -------------------------------------------------------------
        4          SOURCE OF FUNDS:                            OO
- ------------------ -------------------------------------------------------------
        5          CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
                   PURSUANT TO ITEM 2(d) OR 2(e):                            [_]
- ------------------ -------------------------------------------------------------
        6          CITIZENSHIP OR PLACE OF ORGANIZATION:       Delaware

- --------------------------------------------------------------------------------
    NUMBER OF        7    SOLE VOTING POWER:                   200,000
      SHARES
                   ------ ------------------------------------------------------
   BENEFICIALLY      8    SHARED VOTING POWER:                       0
     OWNED BY
                   ------ ------------------------------------------------------
       EACH          9    SOLE DISPOSITIVE POWER:              200,000
    REPORTING
                   ------ ------------------------------------------------------
   PERSON WITH       10   SHARED DISPOSITIVE POWER:                  0
- --------------------------------------------------------------------------------
       11          AGGREGATE AMOUNT BENEFICIALLY OWNED BY REPORTING 
                   PERSON:                                     200,000
- ------------------ -------------------------------------------------------------
       12          CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
                   CERTAIN SHARES:                                           [_]
- ------------------ -------------------------------------------------------------
       13          PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):    6.7%
- ------------------ -------------------------------------------------------------
       14          TYPE OF REPORTING PERSON:                   CO
- ------------------ -------------------------------------------------------------




- ---------------------------------           ------------------------------------
CUSIP No. 09066L105                  13D             Page 3 of 15 Pages
- ---------------------------------           ------------------------------------

- ------------------ -------------------------------------------------------------
        1          NAME OF REPORTING PERSON              GREENWAY PARTNERS, L.P.
                   S.S. OR I.R.S. IDENTIFICATION NO.     13-3714238
                   OF ABOVE PERSON

- ------------------ -------------------------------------------------------------
        2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:     (a) [x]
                                                                         (b) [_]
- ------------------ -------------------------------------------------------------
        3          SEC USE ONLY
- ------------------ ------------------------------------------- -----------------
        4          SOURCE OF FUNDS:                            WC, OO
- ------------------ -------------------------------------------------------------
        5          CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
                   PURSUANT TO ITEM 2(d) OR 2(e):                            [_]
- ------------------ -------------------------------------------------------------
        6          CITIZENSHIP OR PLACE OF ORGANIZATION:       Delaware

- --------------------------------------------------------------------------------
    NUMBER OF        7    SOLE VOTING POWER:                   25,000
      SHARES
                   ------ ------------------------------------------------------
   BENEFICIALLY      8    SHARED VOTING POWER:                      0
     OWNED BY
                   ------ ------------------------------------------------------
       EACH          9    SOLE DISPOSITIVE POWER:              25,000
    REPORTING
                   ------ ------------------------------------------------------
   PERSON WITH       10   SHARED DISPOSITIVE POWER:                 0
- --------------------------------------------------------------------------------
       11          AGGREGATE AMOUNT BENEFICIALLY OWNED BY REPORTING 
                   PERSON:                                     25,000
- ------------------ -------------------------------------------------------------
       12          CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
                   CERTAIN SHARES:                                           [_]
- ------------------ -------------------------------------------------------------
       13          PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):    0.9%
- ------------------ -------------------------------------------------------------
       14          TYPE OF REPORTING PERSON:                   PN
- ------------------ -------------------------------------------------------------




- ---------------------------------           ------------------------------------
CUSIP No. 09066L105                  13D             Page 4 of 15 Pages
- ---------------------------------           ------------------------------------

- ------------------ -------------------------------------------------------------
        1          NAME OF REPORTING PERSON            GREENHOUSE PARTNERS, L.P.
                   S.S. OR I.R.S. IDENTIFICATION NO.   13-3793447
                   OF ABOVE PERSON

- ------------------ -------------------------------------------------------------
        2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:     (a) [x]
                                                                         (b) [_]
- ------------------ -------------------------------------------------------------
        3          SEC USE ONLY
- ------------------ -------------------------------------------------------------
        4          SOURCE OF FUNDS:                            WC, AF, OO
- ------------------ -------------------------------------------------------------
        5          CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
                   PURSUANT TO ITEM 2(d) OR 2(e):                            [_]
- ------------------ -------------------------------------------------------------
        6          CITIZENSHIP OR PLACE OF ORGANIZATION:       Delaware

- --------------------------------------------------------------------------------
    NUMBER OF        7    SOLE VOTING POWER:                        0
      SHARES
                   ------ ------------------------------------------------------
   BENEFICIALLY      8    SHARED VOTING POWER:                 25,000
     OWNED BY
                   ------ ------------------------------------------------------
       EACH          9    SOLE DISPOSITIVE POWER:                   0
    REPORTING
                   ------ ------------------------------------------------------
   PERSON WITH       10   SHARED DISPOSITIVE POWER:            25,000
- --------------------------------------------------------------------------------
       11          AGGREGATE AMOUNT BENEFICIALLY OWNED BY REPORTING 
                   PERSON:                                     25,000
- ------------------ -------------------------------------------------------------
       12          CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
                   CERTAIN SHARES:                                           [_]
- ------------------ -------------------------------------------------------------
       13          PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):    0.9%
- ------------------ -------------------------------------------------------------
       14          TYPE OF REPORTING PERSON:                   PN
- ------------------ -------------------------------------------------------------



- ---------------------------------           ------------------------------------
CUSIP No. 09066L105                  13D             Page 5 of 15 Pages
- ---------------------------------           ------------------------------------

- ------------------ -------------------------------------------------------------
        1          NAME OF REPORTING PERSON              ALFRED D. KINGSLEY
                   S.S. OR I.R.S. IDENTIFICATION NO.     
                   OF ABOVE PERSON

- ------------------ -------------------------------------------------------------
        2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:     (a) [x]
                                                                         (b) [_]
- ------------------ -------------------------------------------------------------
        3          SEC USE ONLY
- ------------------ -------------------------------------------------------------
        4          SOURCE OF FUNDS:                            PF, AF, OO
- ------------------ -------------------------------------------------------------
        5          CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
                   PURSUANT TO ITEM 2(d) OR 2(e):                            [_]
- ------------------ -------------------------------------------------------------
        6          CITIZENSHIP OR PLACE OF ORGANIZATION:       United States

- --------------------------------------------------------------------------------
    NUMBER OF        7    SOLE VOTING POWER:                    74,500
      SHARES
                   ------ ------------------------------------------------------
   BENEFICIALLY      8    SHARED VOTING POWER:                 225,000
     OWNED BY
                   ------ ------------------------------------------------------
       EACH          9    SOLE DISPOSITIVE POWER:               74,500
    REPORTING
                   ------ ------------------------------------------------------
   PERSON WITH       10   SHARED DISPOSITIVE POWER:            225,000
- --------------------------------------------------------------------------------
       11          AGGREGATE AMOUNT BENEFICIALLY OWNED BY REPORTING 
                   PERSON:                                     299,500
- ------------------ -------------------------------------------------------------
       12          CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
                   CERTAIN SHARES:                                           [_]
- ------------------ -------------------------------------------------------------
       13          PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):    10.1%
- ------------------ -------------------------------------------------------------
       14          TYPE OF REPORTING PERSON:                   IN
- ------------------ -------------------------------------------------------------




- ---------------------------------           ------------------------------------
CUSIP No. 09066L105                  13D             Page 6 of 15 Pages
- ---------------------------------           ------------------------------------

- ------------------ -------------------------------------------------------------
        1          NAME OF REPORTING PERSON              GARY K. DUBERSTEIN
                   S.S. OR I.R.S. IDENTIFICATION NO.     
                   OF ABOVE PERSON

- ------------------ -------------------------------------------------------------
        2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:     (a) [x]
                                                                         (b) [_]
- ------------------ -------------------------------------------------------------
        3          SEC USE ONLY
- ------------------ -------------------------------------------------------------
        4          SOURCE OF FUNDS:                            PF, AF, OO
- ------------------ -------------------------------------------------------------
        5          CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
                   PURSUANT TO ITEM 2(d) OR 2(e):                            [_]
- ------------------ -------------------------------------------------------------
        6          CITIZENSHIP OR PLACE OF ORGANIZATION:       United States

- --------------------------------------------------------------------------------
    NUMBER OF        7    SOLE VOTING POWER:                     3,000
      SHARES
                   ------ ------------------------------------------------------
   BENEFICIALLY      8    SHARED VOTING POWER:                 225,000
     OWNED BY
                   ------ ------------------------------------------------------
       EACH          9    SOLE DISPOSITIVE POWER:                3,000
    REPORTING
                   ------ ------------------------------------------------------
   PERSON WITH       10   SHARED DISPOSITIVE POWER:            225,000
- --------------------------------------------------------------------------------
       11          AGGREGATE AMOUNT BENEFICIALLY OWNED BY REPORTING 
                   PERSON:                                     228,000
- ------------------ -------------------------------------------------------------
       12          CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
                   CERTAIN SHARES:                                           [_]
- ------------------ -------------------------------------------------------------
       13          PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):     7.7%
- ------------------ -------------------------------------------------------------
       14          TYPE OF REPORTING PERSON:                   IN
- ------------------ -------------------------------------------------------------



ITEM 1.  SECURITY AND ISSUER.

         This Statement on Schedule 13D (the "Statement") relates to the common
shares, par value $.01 per share (the "Shares"), of BioTime Inc., a California
corporation (the "Company"). The principal executive offices of the Company are
located at 935 Pardee Street, Berkeley, California 94710.

ITEM 2. IDENTITY AND BACKGROUND.

         This Statement is being filed by and on behalf of Greenbelt Corp.
("Greenbelt"), Greenway Partners, L.P. ("Greenway"), Greenhouse Partners, L.P.
("Greenhouse"), Alfred D. Kingsley and Gary K. Duberstein (collectively, the
"Reporting Persons"). Greenbelt is a Delaware corporation. Each of Greenway and
Greenhouse is a Delaware limited partnership. The principal business of
Greenbelt is managing a small number of securities accounts and acting as
financial adviser to the Company. The principal business of Greenway is
investing in securities. The principal business of Greenhouse is being the
general partner of Greenway. The present principal occupation of each of Messrs.
Kingsley and Duberstein is serving as the general partners of Greenhouse. In
addition, Mr. Kingsley is senior managing director, and Mr. Duberstein is
managing director, of Greenway. Also, Mr. Kingsley is president, and Mr.
Duberstein is vice president, secretary and treasurer of Greenbelt. During the
last five years, none of the Reporting Persons has (i) been convicted in a
criminal proceeding or (ii) been a party to a civil proceeding of a judicial or
administrative body of competent jurisdiction and as a result of such proceeding
was or is subject to a judgment, decree or final order enjoining future
violations of, or prohibiting or mandating activities subject to, federal or
state securities laws or finding any violation with respect to such laws. The
business address of each of the Reporting Persons is 277 Park Avenue, 27th
Floor, New York, New York 10017. Messrs. Kingsley and Duberstein are both
citizens of the United States.


                                     Page 7


ITEM 3.  SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

         Greenway purchased an aggregate of 25,000 Shares for total
consideration (including brokerage commissions) of $128,125 derived from the
capital of Greenway and margin indebtedness from Bear Stearns & Co. Inc.

         Mr. Kingsley purchased an aggregate of 74,500 Shares for total
consideration (including brokerage commissions) of $150,363.75 derived from
personal funds and margin indebtedness from Bear Stearns & Co. Inc.

         Mr. Duberstein purchased an aggregate of 3,000 Shares for total
consideration (including brokerage commissions) of $15,375 derived from personal
funds and margin indebtedness from Bear Stearns & Co. Inc.

         Pursuant to an agreement dated September 13, 1995 (the "Consulting
Agreement"), Greenbelt was retained by the Company to be its financial adviser.
As compensation for services as financial adviser, Greenbelt has received from
the Company, as of the date hereof, warrants (the "Warrants") to purchase
200,000 Shares, which Warrants are not exercisable until October 15, 1996. The
terms of the Consulting Agreement and the Warrants are described in Item 6
hereof.

ITEM 4.  PURPOSE OF THE TRANSACTION.

         The information contained in Items 3 and 6 hereof is incorporated
herein by reference.

         The Company approached the executive officers of Greenbelt in August
1995 about providing financial consulting services to the Company and, as noted
above, the Consulting Agreement, which provides for the issuance of the Warrants
to Greenbelt, was signed in September 1995. The Consulting Agreement provides
that Greenbelt (a) will assist the Company in its negotiations with third
parties who may be interested in obtaining rights in the United States

                                     Page 8



and foreign countries to the Company's products and patents, and (b) will
provide financial consulting to the Company, including advice on devising a
capital structure conducive to attracting additional financing from one or more
domestic or international pharmaceutical companies, venture capital funds,
banks, or other sources of private capital.

         Pursuant to the terms of the Consulting Agreement, the Reporting
Persons will receive additional Warrants at the times set forth therein as
described in Item 6. 

         Prior to having had any discussions with the Company, in January 1993, 
March 1994, May 1995 and June 1995, the Reporting Persons purchased an aggregate
of 102,500 Shares, constituting less than five percent of the outstanding 
Shares, because they believed the Company had promising technology for the 
development of synthetic blood plasma expanders.

         The Reporting Persons (i) reserve the right to sell, transfer or
exercise the Warrants, and may from time-to-time (ii) acquire additional Shares
(subject to availability at prices deemed favorable) in the open market, in
privately negotiated transactions or otherwise, or (iii) dispose of Shares at
prices deemed favorable in the open market, in privately negotiated transactions
or otherwise.

ITEM 5.  INTEREST IN SECURITIES OF THE ISSUER.

         (a) As of the date of this Statement, the Reporting Persons
beneficially owned in the aggregate 302,500 Shares constituting 10.2% of the
outstanding Shares. Pursuant to Rule 13d-3 under the Securities and Exchange Act
of 1934, (i) such aggregate number includes 200,000 Shares which may be
purchased upon the exercise of Warrants which first become exercisable on
October 15, 1996 (the "Warrant Shares") and (ii) such percentage of Shares
beneficially owned by the Reporting Persons is determined based upon an
aggregate of 2,972,071 Shares outstanding 


                                     Page 9



consisting of (a) the 2,772,071 Shares which the Company informed the Reporting
Persons was outstanding on August 22, 1996 plus (b) the 200,000 Warrant Shares.
The Reporting Persons may be deemed to have direct beneficial ownership of
Shares as set forth in the following table. In such table, pursuant to Rule
13d-3, the Warrant Shares are deemed outstanding only for determining the
percentage ownership of Shares by Greenbelt, which is the direct beneficial
owner of the 200,000 Warrant Shares which may be purchased upon the exercise of
Warrants commencing on October 15, 1996.

                                                       APPROXIMATE PERCENTAGE
      NAME                 NUMBER OF SHARES            OF OUTSTANDING SHARES
      ----                 ----------------            ---------------------
   Greenbelt                   200,000                       6.7%
    Greenway                    25,000                       0.9%
    Kingsley                    74,500                       2.7%
   Duberstein                    3,000                       0.1%

         Greenbelt has direct beneficial ownership of the 200,000 Warrant
Shares. Each of Messrs. Kingsley and Duberstein, as executive officers and
directors of Greenbelt, may be deemed to beneficially own the Warrant Shares
which Greenbelt beneficially owns.

         Greenhouse, as the general partner of Greenway, may be deemed to own
beneficially (as that term is defined in Rule 13d-3) Shares which Greenway may
be deemed to possess direct beneficial ownership. Each of Messrs. Kingsley and
Duberstein, as general partners of Greenhouse, may be deemed to beneficially own
Shares which Greenhouse may be deemed to beneficially own. Each of Messrs.
Kingsley and Duberstein disclaim beneficial ownership of such Shares for all
other purposes.

         (b) If Greenbelt were to exercise in full the Warrants, which become
exercisable on October 15, 1996, it would then have the sole power to vote or
direct the vote of 200,000 Warrant Shares and the sole power to dispose or
direct the disposition of such Warrant Shares.

                                    Page 10



Messrs. Kingsley and Duberstein may be deemed to share with Greenbelt the power
to vote or to direct the vote and to dispose or to direct the disposition of any
Warrant Shares.

         Greenway has the sole power to vote or direct the vote of 25,000 Shares
and the sole power to dispose or direct the disposition of such Shares.
Greenhouse and Messrs. Kingsley and Duberstein may be deemed to share with
Greenway the power to vote or to direct the vote and to dispose or to direct the
disposition of such Shares.

         Mr. Kingsley has the sole power to vote or direct the vote of 74,500
Shares and the sole power to dispose or direct the disposition of such Shares.

         Mr. Duberstein has the sole power to vote or direct the vote of 3,000
Shares and the sole power to dispose or direct the disposition of such Shares.

         (c) During the past sixty days, pursuant to the terms of the Consulting
Agreement, the Company issued to Greenbelt, on July 15, 1996, Warrants to
purchase 25,000 Shares at a purchase price of $30.04 per share exercisable from
October 15, 1996 to July 15, 2001.

         (d) No other person is known to have the right to receive or the power
to direct the receipt of dividends from, or the proceeds from the sale of, the
Shares or the Warrants.

         (e) Not applicable.

ITEM 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO
        SECURITIES OF THE ISSUER.

         To the best of the knowledge of the Reporting Persons, there are no
contracts, arrangements, understandings or relationships (legal or otherwise)
among the Reporting Persons or between the Reporting Persons and any other
person with respect to any securities of the Company, including but not limited
to transfer or voting of any of the securities, finder's fees, joint


                                    Page 11



ventures, loan or option arrangements, puts or calls, guarantees of profits,
division of profits or loss, or the giving or withholding of proxies, except as
follows:

         The Consulting Agreement provides that Greenbelt (a) will assist the
Company in its negotiations with third parties who may be interested in
obtaining rights in the United States and foreign countries to the Company's
products and patents, and (b) will provide financial consulting to the Company,
including advice on devising a capital structure conducive to attracting
additional financing from one or more domestic or international pharmaceutical
companies, venture capital funds, banks, or other sources of private capital. As
compensation for the services of Greenbelt to be performed under the Consulting
Agreement, the Company (i) issued to the Financial Adviser on September 13, 1995
warrants to purchase 100,000 Shares at an exercise price of $6 per share,
exercisable from October 15, 1996 through October 15, 2000, and (ii) agreed to
issue on the following quarterly dates additional warrants to purchase the
number of additional Shares indicated below, exercisable from the later of (w)
October 15, 1996 and (x) their date of issuance, through the applicable
Expiration Date indicated below, at a price equal to the greater of (y) 150% of
the average of the last sale prices of the Shares during the three months prior
to the issuance of the additional warrants, and (z) $6:

                              WARRANTS FOR
         DATE OF ISSUANCE     ADDITIONAL SHARES         EXPIRATION DATE
         ----------------     -----------------         ---------------
         October 15, 1995     25,000                    October 15, 2000
         January 15, 1996     25,000                    January 15, 2001
         April 15, 1996       25,000                    April 15, 2001
         July 15, 1996        25,000                    July 15, 2001
         October 15, 1996     25,000                    October 15, 2001
         January 15, 1997     25,000                    January 15, 2002
         April 15, 1997       25,000                    April 15, 2002
         July 15, 1997        25,000                    July 15, 2002

         The Warrants issued on October 15, 1995; January 15, 1996; April 15,
1996 and July 15, 1996 had a purchase price per Share of $6; $6; $7.32 and
$30.04, respectively.

                                    Page 12


         The Consulting Agreement shall terminate on October 1, 1997, unless
sooner terminated by the Company or Greenbelt upon 30 days prior written notice,
provided that if the Company terminates the Consulting Agreement the right of
Greenbelt to receive the next issuance of Warrants to purchase 25,000 additional
Shares shall be accelerated.

         The number of Shares for the which the Warrants may be exercised are
subject to the anti-dilution protection set forth in the Warrant Agreement dated
as of September 13, 1995 between the Company and Greenbelt (the "Warrant
Agreement"). As set forth in the Consulting Agreement, the Company has granted
to Greenbelt certain registration rights for the Warrants and Warrant Shares.

         The foregoing description of the Consulting Agreement and the Warrant
Agreement (which contains a form of Warrant) is qualified in its entirety to the
full text of such agreements which are filed herewith as exhibits and
incorporated herein by reference.

         In addition, the partnership agreement of Greenway contains provisions
whereby its general partner (i.e., Greenhouse) will receive annually a certain
percentage of realized and unrealized profits, if any, derived from the
partnership's investments.

ITEM 7.  MATERIAL TO BE FILED AS EXHIBITS.

         The following Exhibits are filed herewith:

         1.   Joint Filing Agreement.

         2.   Consulting Agreement dated September 13, 1995 between BioTime
              Inc. and Greenbelt Corp.

         3.   Warrant Agreement dated as of September 13, 1995 between BioTime
              Inc. and Greenbelt Corp.

                                    Page 13


                                    SIGNATURES

         After reasonable inquiry and to the best of their knowledge and belief,
the undersigned certify that the information contained in this Statement is
true, complete and correct.

Dated:   August 22, 1996

GREENHOUSE PARTNERS, L.P.                    GREENWAY PARTNERS, L.P.

                                             By:  Greenhouse Partners, L.P., its
                                                    general partner
By:/s/ Gary K. Duberstein   
    Gary K. Duberstein, general              By:/s/ Gary K. Duberstein       
      partner                                   Gary K. Duberstein, general
                                                  partner

                                             GREENBELT CORP.

                                             By:/s/ Alfred D. Kingsley
                                                Alfred D. Kingsley, President



                                                  /s/ Alfred D. Kingsley    
                                                      Alfred D. Kingsley

                                                  /s/ Gary K. Duberstein
                                                      Gary K. Duberstein





                                    Page 14



                                 EXHIBIT INDEX


    Exhibit No.   Exhibit Description
    -----------  -------------------

           1.   Joint Filing Agreement.

           2.   Consulting Agreement dated September 13, 1995 between BioTime
                Inc. and Greenbelt Corp.

           3.   Warrant Agreement dated as of September 13, 1995 between BioTime
                Inc. and Greenbelt Corp.


                                     Page 15


                                                                       Exhibit 1

                             JOINT FILING AGREEMENT

         In accordance with Rule 13d-1(f) under the Securities Exchange Act of
1934, as amended, the persons named below agree to the joint filing on behalf of
each of them of a statement on Schedule 13D (including amendments thereto) with
respect to the common stock, no par value, of BioTime Inc., and further agree
that this Joint Filing Agreement be included as an Exhibit to such joint filing.
In evidence thereof, the undersigned, hereby execute this Agreement this 22nd
day of August, 1996. 


GREENHOUSE PARTNERS, L.P.                    GREENWAY PARTNERS, L.P.

                                             By:  Greenhouse Partners, L.P., its
                                                    general partner
By:/s/ Gary K. Duberstein   
    Gary K. Duberstein, general              By:/s/ Gary K. Duberstein       
      partner                                   Gary K. Duberstein, general
                                                  partner

                                             GREENBELT CORP.

                                             By:/s/ Alfred D. Kingsley
                                                Alfred D. Kingsley, President



                                                  /s/ Alfred D. Kingsley    
                                                      Alfred D. Kingsley

                                                  /s/ Gary K. Duberstein
                                                      Gary K. Duberstein



                                                                       Exhibit 2


                                 GREENBELT CORP.
                           277 PARK AVENUE, 27TH FLOOR
                               NEW YORK, NY 10017
                               TEL. (212) 350-5100
                               FAX. (212) 350-5253






                                                  September 13, 1995

Paul Segall, Ph.D.
President and Chief Executive
 Officer
BioTime, Inc.
935 Pardee Street
Berkeley, CA   94710

Dear Mr. Segall:

         This letter agreement (the "Agreement") confirms the retention of
Greenbelt Corp. (the "Financial Adviser") by BioTime, Inc. ("BioTime") to act as
its financial adviser on the following terms and conditions.

         1. The Financial Adviser (a) will assist BioTime in its negotiations
with third parties who may be interested in obtaining rights in the United
States and foreign countries to BioTime's products and patents, and (b) will
provide financial consulting to BioTime, including advice on devising a capital
structure conducive to attracting additional financing from one or more domestic
or international pharmaceutical companies, venture capital funds, banks, or
other sources of private capital.

         2. (a) As compensation for the services of the Financial Adviser to be
performed hereunder, BioTime hereby (i) issues to the Financial Adviser on the
date hereof warrants to purchase 100,000 shares of common stock of BioTime
("Common Stock") at an exercise price of $6 per share, exercisable from October
15, 1996 through October 15, 2000, and (ii) agrees to issue on the following
quarterly dates additional warrants to purchase the number of additional shares
of Common Stock indicated below, exercisable from the later of (w) October 15,
1996 and (x) their date of issuance, through the applicable Expiration Date
indicated below, at a price equal to the greater of (y) 150% of the average of
the last sale prices of the Common Stock during the three months prior to the
issuance of the additional warrants, and (z) $6:



                                     Page 1




                               WARRANTS FOR              EXPIRATION
         DATE OF ISSUANCE      ADDITIONAL SHARES         DATE      
         ----------------      -----------------         ----
         October 15, 1995      25,000                    October 15, 2000
         January 15, 1996      25,000                    January 15, 2001
         April 15, 1996        25,000                    April 15, 2001
         July 15, 1996         25,000                    July 15, 2001
         October 15, 1996      25,000                    October 15, 2001
         January 15, 1997      25,000                    January 15, 2002
         April 15, 1997        25,000                    April 15, 2002
         July 15, 1997         25,000                    July 15, 2002


         (b) The warrants shall be issued in the form annexed hereto as Exhibit
A and shall be exercisable, in whole or in part, upon written notice to BioTime.
BioTime agrees to reserve a sufficient number of shares of authorized Common
Stock for issuance pursuant to the warrants granted and to be granted hereunder.
The number of shares of Common Stock for which the warrants may be exercised
shall be subject to reasonable and customary anti-dilution protection.

         . (c) BioTime agrees, at its expense, upon written request from the
Financial Adviser, to register under the Securities Act of 1933 (the "1933
Act"), the warrants and shares of Common Stock issued or issuable upon the
exercise of such warrants (collectively, the "Registrable Securities") and to
take such other actions as may be necessary to allow such Registrable Securities
to be freely tradable, without restrictions, in compliance with all regulatory
requirements. BioTime shall not be obligated to file a registration statement
with respect to the Registrable Securities prior to October 15, 1996. A written
request for registration shall specify the type and quantity of the Registrable
Securities intended to be sold, the plan of distribution and the identity of the
sellers, which may include the Financial Adviser and assignees of its rights
hereunder (collectively, "Selling Securities Holders"), and whether the
registration shall be pursuant to an underwritten public offering or a "shelf"
registration pursuant to Rule 415 (or similar rule that may be adopted by the
Securities and Exchange Commission). BioTime shall not be obligated to file more
than two such registration statements, other than registration statements on
Form S-3. BioTime shall keep such registration statements effective for a period
of at least nine months, except that registration statements on Form S-3 shall
be kept effective for at least three years (or such lesser period as the parties
may agree (but in no event beyond the completion of the distribution or
distributions being made pursuant thereto)); provided that if the registration
statement relates to warrants, BioTime will, to the extent required by law, keep
such registration statement effective with respect to Common Stock issuable upon
exercise of the warrants until all such warrants shall have been exercised or
have expired. BioTime shall utilize Form S-3 if it qualifies for such use.
BioTime shall make all filings required with respect to the registration
statements and will use its best efforts to cause such filings to become
effective, so that the Registrable Securities being registered shall be
registered or qualified for sale under the securities or blue sky laws of such
jurisdictions as shall be reasonably appropriate for distribution of the
securities covered by the registration statement. BioTime will furnish to the
Selling Securities Holders such numbers of copies of a prospectus, including a
preliminary prospectus, in conformity with the requirements of the 1933 Act and
such other related documents as the Selling Securities Holders may reasonably
request in order to effect the sale of the Registrable Securities. To effect any
offering pursuant to a registration statement under this paragraph 2, BioTime
shall enter into an agreement containing customary representations and
warranties, and indemnification and

                                     Page 2



contribution provisions, all for the benefit of Selling Securities Holders, and,
in the case of an underwritten public offering, an underwriting agreement with
an investment banking firm selected by the Financial Adviser and reasonably
acceptable to BioTime, containing such customary representations and warranties,
and indemnification and contribution provisions.

         (d) If, at any time, BioTime proposes to register any of its securities
under the 1933 Act (otherwise than pursuant to paragraph 2(c) above or on a Form
S-8 if such form cannot be used for registration of the Registrable Securities
pursuant to its terms), BioTime shall, as promptly as practicable, give written
notice to the Financial Adviser. BioTime shall include in such registration
statement any Registrable Securities proposed to be sold by the Selling
Securities Holders. Notwithstanding the foregoing, if the offering of BioTime's
securities is to be made through underwriters, BioTime shall not be required to
include Registrable Securities if and to the extent that the managing
underwriter reasonably believes in good faith that such inclusion would
materially adversely affect such offering unless the Selling Securities Holders
agree to postpone their sales until 10 days after the distribution is completed.

         (e) At such time as the Financial Adviser requests to register warrants
pursuant to this paragraph 2, BioTime shall use its best efforts to list the
warrants on all national securities exchanges on which the Common Stock is then
listed if requested by the Financial Adviser.

         (f) BioTime shall pay the cost of the registration statements filed
pursuant to this paragraph 2, including without limitation all registration and
filing fees, fees and expenses of compliance with securities or blue sky laws
(including counsel's fees and expenses in connection therewith), printing
expenses, messenger and delivery expenses, internal expenses of BioTime, listing
fees and expenses, and fees and expenses of BioTime's counsel, independent
accountants and other persons retained or employed by BioTime. Selling
Securities Holders shall pay any underwriters discounts applicable to
Registrable Securities.

         (g) All certificates evidencing the Registrable Securities shall bear
an appropriate legend to the effect that the securities have not been registered
under the 1933 Act and may not be sold or transferred in the absence of such
registration or an exemption therefrom. BioTime agrees that upon the sale of
Registrable Securities pursuant to a registration statement or an exemption, it
will, upon the presentation to its transfer agent of the certificates containing
such legend, remove such legend. BioTime further agrees to remove the legend at
such time as registration under the 1933 Act shall no longer be required.

         3. BioTime agrees to indemnify and hold harmless the Financial Adviser
and its officers, affiliates, employees, agents, assignees and controlling
persons (the Financial Adviser and each such person being hereinafter called an
"Indemnified Person") against any and all losses, damages, claims, judgments,
and expenses (including reasonable legal expenses), directly or indirectly,
caused by, relating to, or arising out of or in connection with the Financial
Adviser acting for BioTime hereunder or this Agreement. Biotime also agrees that
an Indemnified Person shall not have any liability to BioTime or to any person
(including without limitation, BioTime's shareholders) claiming through BioTime
or in connection with the engagement of the Financial Adviser hereunder, except
to the extent that any such liability is found in a final judgment by a court of
competent jurisdiction (not subject to further appeal) to have resulted
primarily from the Indemnified Person's gross negligence or willful misconduct.

                                     Page 3



         4. In addition to issuing the warrants and shares of Common Stock
described in paragraph 2 above, BioTime agrees to reimburse the Financial
Adviser, upon written request from time to time, for all reasonable
out-of-pocket expenses incurred in connection with its engagement hereunder.

         5. This Agreement shall terminate on October 1, 1997, unless sooner
terminated pursuant to the following sentence. Either party may terminate this
Agreement upon 30 days prior written notice to the other party, provided that if
BioTime terminates this Agreement the right of the Financial Adviser to receive
the next issuance of warrants to purchase 25,000 additional shares of Common
Stock shall be accelerated and BioTime shall issue such warrants to the
Financial Adviser contemporaneously with transmitting the notice of termination.
Notwithstanding the termination of this Agreement for any reason pursuant to
this paragraph 5, BioTime's obligations to the Financial Adviser under
paragraphs 2(b), 2(c), 2(d), 2(e), 2(f), 2(g), 3, 5, and 8 of this Agreement
shall continue.

         6. BioTime hereby represents and warrants to the Financial Adviser that
BioTime has full legal right, power and authority to enter into and perform this
Agreement and to issue the warrants and shares of Common Stock issuable upon the
exercise of such warrants, and that all transactions contemplated hereby have
been duly authorized by all necessary corporate action on behalf of BioTime. The
Financial Adviser hereby represents and warrants to BioTime that it is acquiring
the warrants for investment purposes and not with a view toward public
distribution thereof.

         7. The validity and interpretation of this Agreement shall be governed
by the law of the State of New York applicable to agreements made and to be
fully performed therein.

         8. The benefits of this Agreement shall inure to the respective
successors and assigns of the parties hereto, each Indemnified Person, Selling
Securities Holders, and their successors and assigns and representatives, and
the obligations and liabilities assumed in this Agreement by the parties hereto
shall be binding upon their respective successors and assigns. The Financial
Adviser may assign the warrants (or the shares of Common Stock issuable upon the
exercise of such warrants) to Alfred D. Kingsley or Gary K. Duberstein or as
they may otherwise direct.

         9. Any notice given pursuant to the provisions of this Agreement shall
be in writing and shall be mailed or delivered (a) if to BioTime, to BioTime,
Inc., 935 Pardee Street, Berkeley, CA 94710, Attention: Paul Segall, Ph.D., or
(b) if to the Financial Adviser, to Greenbelt Corp., 277 Park Avenue, 27th
Floor, New York, New York 10017, Attention: Gary K. Duberstein, Esq.

         10. For the convenience of the parties, this Agreement may be executed
by the parties hereto in counterparts. Each such counterpart shall be, and shall
be deemed to be, an original instrument, but all such counterparts taken
together shall constitute one and the same Agreement. This Agreement may not be
modified or amended except in writing signed by the parties hereto.


                                     Page 4




         If the foregoing correctly sets forth our agreement, we would
appreciate your signing the enclosed copy of this letter in the space provided
and returning it to us.

                                                Very truly yours,

                                                GREENBELT CORP.


                                                By: /s/ Alfred D. Kingsley
                                                    Name: Alfred D. Kingsley
                                                    Title: President

Confirmed and agreed to this
13th day of September, 1995

BIOTIME, INC.


By: /s/ Paul Segall
     Name: Paul Segall
     Title: President







                                                                       Exhibit 3


                                 ---------------

                                Warrant Agreement

                         Dated as of September 13, 1995

                                 ---------------






            WARRANT AGREEMENT, dated as of September 13, 1995, between Biotime,
Inc., a California corporation (the "Company"), and Greenbelt Corp., a Delaware
corporation (the "Financial Advisor").

            The Company proposes to issue Common Share Purchase Warrants, as
hereinafter described (the "Warrants"), to purchase up to an aggregate of
300,000 shares of its Common Shares, no par value (the "Common Stock") (the
shares of Common Stock issuable upon exercise of the Warrants being referred to
herein as the "Warrant Shares"), in connection with the agreement, dated
September 13, 1995 (the "Consulting Agreement"), between the Company and the
Financial Advisor; each Warrant entitling the holder thereof to purchase one
share of Common Stock.

            In consideration of the foregoing and for the purpose of defining
the terms and provisions of the Warrants and the respective rights and
obligations thereunder of the Company and the registered owners of the Warrants
(the "Holders"), the Company and the Financial Advisor hereby agree as follows:

            SECTION 1. Issuance of Warrants; Term of Warrants. Concurrently with
the execution and delivery of this Agreement and the Consulting Agreement, the
Company is issuing and delivering to the Financial Advisor Warrants to purchase
100,000 Warrant Shares, which Warrants shall be represented by a certificate in
substantially the form of Exhibit A hereto. Subject to the terms of this
Agreement, a Holder of any of such 100,000 Warrants shall have the right, which
may be exercised at any time after 9:00 a.m., New York time, on October 15,
1996, and prior to 5:00 p.m., New York Time on October 15, 2000 (the "Expiration
Date"), to purchase from the Company the number of fully paid and nonassessable
Warrant Shares which the Holder may at the time be entitled to purchase upon
exercise of any of such 100,000 Warrants. The Company will issue and deliver
additional Warrants on such dates and with such Expiration Dates as indicated
below, which additional Warrants shall be represented by certificates
substantially in the form of Exhibit A hereto delivered on the applicable dates
of issuance:

                              Additional        Expiration
Date of Issuance              Warrants          Date
- ----------------              ----------        ----
October 15, 1995              25,000            October 15, 2000
January 15, 1996              25,000            January 15, 2001
April 15, 1996                25,000            April 15, 2001
July 15, 1996                 25,000            July 15, 2001



                                  1




October 15, 1996              25,000            October 15, 2001
January 15, 1997              25,000            January 15, 2002
April 15, 1997                25,000            April 15, 2002
July 15, 1997                 25,000            July 15, 2002

; provided, however, in the event that the Consulting Agreement is terminated
prior to July 15, 1997, the Company shall issue and deliver to the Financial
Advisor, as of the date of such termination, the 25,000 additional Warrants that
would otherwise have been issuable on the next succeeding date of issuance set
forth above and, following such issuance and delivery, no additional Warrants
shall be issued or delivered hereunder.

Subject to the terms of this Agreement, a Holder of any of such additional
Warrants shall have the right, which may be exercised at any time after 9:00
a.m., New York time, on the later of (a) October 15, 1996 and (b) the date of
issuance, and prior to 5:00 p.m., New York time on the applicable Expiration
Date, to purchase from the Company the number of fully paid and nonassessable
Warrant Shares which the Holder may at the time be entitled to purchase upon
exercise of any of such additional Warrants.

            SECTION 2.  Transferability and Form of Warrant.

            2.1 Registration. The Warrants shall be numbered and shall be
registered on the books of the Company (the "Warrant Register") as they are
issued. The Company and the Warrant Agent (if appointed) shall be entitled to
treat the Holder of any Warrant as the owner in fact thereof for all purposes
and shall not be bound to recognize any equitable or other claim or interest in
such Warrant on the part of any other person, and shall not be liable for any
registration of transfer of any Warrants which are registered or to be
registered in the name of a fiduciary or the nominee of a fiduciary unless made
with the actual knowledge that a fiduciary or nominee is committing a breach of
trust in requesting such registration or transfer, or with such knowledge of
such facts that its participation therein amounts to bad faith. The Warrants
shall initially be registered in the name of the Financial Advisor.

            2.2 Restrictions on Exercise and Transfer. The Warrants may not be
exercised, sold, pledged, hypothecated, transferred or assigned, in whole or in
part, unless a registration statement under the Securities Act of 1933, as
amended (the "Act"), and under any applicable state securities laws is effective
therefor or, an exemption from such registration is then available and the
Holder shall



                                        2



have delivered an opinion of counsel addressed to the Company to such effect;
provided, that such opinion shall be in form and substance and from counsel
reasonably satisfactory to the Company. Any exercise, sale, pledge,
hypothecation, transfer, or assignment in violation of the foregoing restriction
shall be deemed null and void and of no binding effect. The Company shall be
entitled to obtain, as a condition precedent to its issuance of any certificates
representing Warrant Shares or any other securities issuable upon any exercise
of a Warrant, a letter or other instrument from the Holder containing such
covenants, representations or warranties by such Holder as reasonably deemed
necessary by Company to effect compliance by the Company with the requirements
of applicable federal and/or state securities laws.

            2.3 Transfer. Subject to Section 2.2, the Warrants shall be
transferable only on the Warrant Register upon delivery thereof duly endorsed by
the Holder or by his duly authorized attorney or representative, or accompanied
by proper evidence of succession, assignment or authority to transfer, which
endorsement shall be guaranteed by a bank or trust company or a broker or dealer
which is a member of the National Association of Securities Dealers, Inc. In all
cases of transfer by an attorney, the original power of attorney, duly approved,
or a copy thereof, duly certified, shall be deposited and remain with the
Company (or the Warrant Agent, if appointed). In case of transfer by executors,
administrators, guardians or other legal representatives, duly authenticated
evidence of their authority shall be produced, and may be required to be
deposited and remain with the Company (or the Warrant Agent, if appointed) in
its discretion. Upon any registration of transfer, the Company shall execute and
deliver (or if appointed, the Warrant Agent shall countersign and deliver) a new
Warrant or Warrants to the persons entitled thereto.

            2.4 Form of Warrant. The text of the Warrant and of the Purchase
Form shall be substantially as set forth in Exhibit A attached hereto. The price
per Warrant Share and the number of Warrant Shares issuable upon exercise of
each Warrant are subject to adjustment upon the occurrence of certain events,
all as hereinafter provided. The Warrants shall be executed on behalf of the
Company by its Chairman of the Board, President or one of its Executive or
Senior Vice Presidents, under its corporate seal reproduced thereon attested by
its Secretary or Assistant Secretary. The signature of any such officers on the
Warrants may be manual or facsimile, provided, however, that the signature of
any



                                        3


such officers must be manual until such time as a Warrant Agent is appointed.

            Warrants bearing the manual or facsimile signatures of individuals
who were at any time the proper officers of the Company shall bind the Company,
notwithstanding that such individuals or any one of them shall have ceased to
hold such offices prior to the delivery of such Warrants or did not hold such
offices on the date of this Agreement.

            In the event that the Company shall appoint a Warrant Agent to act
on its behalf in connection with the issuance, division, transfer, exchange or
exercise of Warrants, the Warrants issued after the date of such appointment
shall be dated as of the date of countersignature thereof by the Warrant Agent
either upon initial issuance or upon division, exchange, substitution or
transfer. Until such time as the Company shall appoint a Warrant Agent, Warrants
shall be dated as of the date of execution thereof by the Company either upon
initial issuance or upon division, exchange, substitution or transfer.

            SECTION 3. Countersignature of Warrants. In the event that the
Company shall appoint a Warrant Agent to act on its behalf in connection with
the issuance, division, transfer, exchange or exercise of Warrants, the Warrants
issued after the date of such appointment shall be countersigned by the Warrant
Agent (or any successor to the Warrant Agent then acting as warrant agent) and
shall not be valid for any purpose unless so countersigned. Warrants may be
countersigned, however, by the Warrant Agent (or by its successor as warrant
agent hereunder) and may be delivered by the Warrant Agent, notwithstanding that
the persons whose manual or facsimile signatures appear thereon as proper
officers of the Company shall have ceased to be such officers at the time of
such countersignature, issuance or delivery. The Warrant Agent (if so appointed)
shall, upon written instructions of the Chairman of the Board, the President, an
Executive or Senior Vice President, the Treasurer or the Controller of the
Company, countersign, issue and deliver Warrants entitling the Holders thereof
to purchase not more than 300,000 Warrant Shares (subject to adjustment pursuant
to Section 10 hereof) and shall countersign and deliver Warrants as otherwise
provided in this Agreement.

            SECTION 4. Exchange of Warrant Certificates. Each Warrant
certificate may be exchanged, at the option of the Holder thereof, for another
Warrant certificate or



                                        4



Warrant certificates in different denominations entitling the Holder or Holders
thereof to purchase a like aggregate number of Warrant Shares as the certificate
or certificates surrendered then entitle each Holder to purchase. Any Holder
desiring to exchange a Warrant certificate or certificates shall make such
request in writing delivered to the Company at its principal office (or, if a
Warrant Agent is appointed, the Warrant Agent at its principal office) and shall
surrender, properly endorsed, the certificate or certificates to be so
exchanged. Thereupon, the Company (or, if appointed, the Warrant Agent) shall
execute and deliver to the person entitled thereto a new Warrant certificate or
certificates, as the case may be, as so requested, in such name or names as such
Holder shall designate.

            SECTION 5.  Exercise of Warrants; Listing.

            5.1 Exercise of Warrants. A Warrant may be exercised upon surrender
of the certificate or certificates evidencing the Warrants to be exercised,
together with the form of election to purchase on the reverse thereof duly
filled in and signed, which signature shall be guaranteed by a bank or trust
company or a broker or dealer which is a member of the National Association of
Securities Dealers, Inc., to the Company at its principal office (or if
appointed, the principal office of the Warrant Agent) and upon payment of the
Warrant Price (as defined in and determined in accordance with the provisions of
Sections 9 and 10 hereof) to the Company (or if appointed, to the Warrant Agent
for the account of the Company), for the number of Warrant Shares in respect of
which such Warrants are then exercised. Payment of the aggregate Warrant Price
(defined in Section 9 herein) shall be made in cash or by certified or bank
cashier's check.

            Subject to Section 6 hereof, upon the surrender of the Warrant and
payment of the Warrant Price as aforesaid, the Company (or if appointed, the
Warrant Agent) shall cause to be issued and delivered with all reasonable
dispatch to or upon the written order of the Holder and in such name or names as
the Holder may designate, a certificate or certificates for the number of full
Warrant Shares so purchased upon the exercise of such Warrant, together with
cash, as provided in Section 11 hereof, in respect of any fractional Warrant
Shares otherwise issuable upon such surrender. Such certificate or certificates
shall be deemed to have been issued and any person so designated to be named
therein shall be deemed to have become a holder of record of such Warrant Shares
as of the date of the surrender of such



                                        5



Warrants and payment of the Warrant Price, as aforesaid. The rights of purchase
represented by the Warrant shall be exercisable, at the election of the Holder
thereof, either in full or from time to time in part and, in the event that a
certificate evidencing the Warrant is exercised in respect of less than all of
the Warrant Shares purchasable on such exercise at any time prior to the date of
expiration of the Warrant, a new certificate evidencing the unexercised portion
of the Warrant will be issued, and the Warrant Agent (if so appointed) is hereby
irrevocably authorized to countersign and to deliver the required new Warrant
certificate or certificates pursuant to the provisions of this Section and
Section 3 hereof, and the Company, whenever required by the Warrant Agent (if
appointed), will supply the Warrant Agent with Warrant certificates duly
executed on behalf of the Company for such purpose.

            5.2 Listing of Shares on Securities Exchange; Exchange Act
Registration. The Company will promptly use its best efforts to cause the
Warrant Shares to be listed, subject to official notice of issuance, on all
national securities exchanges on which the Common Stock is listed and whose
rules and regulations require such listing, as soon as possible following the
date hereof.

            The Company will promptly notify the Holders in the event that the
Company plans to register the Warrants with the Securities and Exchange
Commission under the Securities Exchange Act of 1934, as amended (the "Exchange
Act").

            SECTION 6. Payment of Taxes. The Company will pay all documentary
stamp taxes, if any, attributable to the initial issuance of Warrant Shares upon
the exercise of Warrants; provided, however, that the Company shall not be
required to pay any tax or taxes which may be payable in respect of any transfer
involved in the issue or delivery of any Warrant or certificates for Warrant
Shares in a name other than that of the registered Holder of such Warrants.

            SECTION 7. Mutilated or Missing Warrants. In case any of the
certificates evidencing the Warrants shall be mutilated, lost, stolen or
destroyed, the Company may in its discretion issue and deliver (and, if
appointed, the Warrant Agent shall countersign and deliver) in exchange and
substitution for and upon cancellation of the mutilated Warrant certificate, or
in lieu of and substitution for the Warrant certificate lost, stolen or
destroyed, a new Warrant certificate of like tenor, but only upon receipt of
evidence reasonably satisfactory to the Company and the Warrant Agent



                                        6



(if so appointed) of such loss, theft or destruction of such Warrant and an
indemnity or bond, if requested, also reasonably satisfactory to them. An
applicant for such a substitute Warrant certificate shall also comply with such
other reasonable regulations and pay such other reasonable charges as the
Company (or the Warrant Agent, if so appointed) may prescribe.

            SECTION 8. Reservation of Warrant Shares; Purchase and Cancellation
of Warrants.

            8.1 Reservation of Warrant Shares. There have been reserved, and the
Company shall at all times keep reserved, out of its authorized Common Stock, a
number of shares of Common Stock sufficient to provide for the exercise of the
rights of purchase represented by the outstanding Warrants and any additional
Warrants issuable hereunder. The Transfer Agent for the Common Stock and every
subsequent transfer agent for any shares of the Company's capital stock issuable
upon the exercise of any of the rights of purchase aforesaid will be irrevocably
authorized and directed at all times to reserve such number of authorized shares
as shall be required for such purpose. The Company will keep a copy of this
Agreement on file with the Transfer Agent for the Common Stock and with every
subsequent transfer agent for any shares of the Company's capital stock issuable
upon the exercise of the rights of purchase represented by the Warrants. The
Warrant Agent, if appointed, will be irrevocably authorized to requisition from
time to time from such Transfer Agent the stock certificates required to honor
outstanding Warrants upon exercise thereof in accordance with the terms of this
Agreement. The Company will supply such Transfer Agent with duly executed stock
certificates for such purposes and will provide or otherwise make available any
cash which may be payable as provided in Section 11 hereof. The Company will
furnish such Transfer Agent a copy of all notices of adjustments and
certificates related thereto, transmitted to each Holder pursuant to subsection
10.3 hereof.

            8.2 Purchase of Warrants by the Company. The Company shall have the
right, except as limited by law, other agreements or herein, with the consent of
the Holder, to purchase or otherwise acquire Warrants at such times, in such
manner and for such consideration as it may deem appropriate.

            8.3 Cancellation of Warrants. In the event the Company shall
purchase or otherwise acquire Warrants, the same shall thereupon be cancelled
and retired. The Warrant



                                        7



Agent (if so appointed) shall cancel any Warrant surrendered for exchange,
substitution, transfer or exercise in whole or in part.

            SECTION 9. Warrant Price. Subject to any adjustments required by
Section 10 hereof, the price per share at which Warrant Shares shall be
purchasable upon exercise of a Warrant (as to any particular Warrant, the
"Warrant Price") shall be a price which shall be the greater of (a) the average
of the last sale prices per share of Common Stock, as reported on the National
Association of Securities Dealers, Inc. Automated Quotations ("NASDAQ") System,
on each trading day during the three month period prior to the date of issuance
of the Warrants multiplied by 150%, and (b) six dollars ($6.00); provided,
however, that the Warrant Price of the Warrants issued as of September 13, 1995
is six dollars ($6.00) and, provided, further, in the event that the last sale
prices of the Common Stock for the period indicated in clause (a) above are not
reported on NASDAQ, clause (a) shall be deemed to refer to the average market
price of the Common Stock during such period, as reasonable determined by the
Board of Directors of the Company on the basis of such quotations as are
available, multiplied by 150%.

            SECTION 10. Adjustment of Warrant Price and Number of Warrant
Shares. The number and kind of securities purchasable upon the exercise of each
Warrant and the Warrant Price shall be subject to adjustment from time to time
upon the happening of certain events, as hereinafter defined.

            10.1 Adjustments. The number of Warrant Shares purchasable upon the
exercise of each Warrant and the Warrant Price shall be subject to adjustment as
follows:

                  (a) In the event that the Company shall (i) pay a dividend in
shares of Common Stock or make a distribution in shares of Common Stock, (ii)
subdivide its outstanding shares of Common Stock, (iii) combine its outstanding
shares of Common Stock into a smaller number of shares of Common Stock or (iv)
reclassify or change (including a change to the right to receive, or a change
into, as the case may be (other than with respect to a merger or consolidation
pursuant to the exercise of appraisal rights), shares of stock, other
securities, property, cash or any combination thereof) its Common Stock
(including any such reclassification or change in connection with a
consolidation or merger in which the Company is the surviving corporation), the
number of Warrant Shares



                                        8



purchasable upon exercise of each Warrant immediately prior thereto shall be
adjusted so that the Holder of each Warrant shall be entitled to receive the
kind and number of Warrant Shares or other securities of the Company or other
property which he would have owned or have been entitled to receive after the
happening of any of the events described above, had such Warrant been exercised
immediately prior to the happening of such event or any record date with respect
thereto. An adjustment made pursuant to this paragraph (a) shall become
effective immediately after the effective date of such event retroactive to the
record date, if any, for such event.

                  (b) In case the Company shall issue rights, options or
warrants to all holders of its outstanding Common Stock, without any charge to
such holders, entitling them to subscribe for or purchase shares of Common Stock
at a price per share which is lower at the record date mentioned below than the
then current market price per share of Common Stock (as defined in paragraph (d)
below), the number of Warrant Shares thereafter purchasable upon the exercise of
each Warrant shall be determined by multiplying the number of Warrant Shares
theretofore purchasable upon exercise of each Warrant by a fraction, of which
the numerator shall be the number of shares of Common Stock outstanding on the
date of issuance of such rights, options or warrants plus the number of
additional shares of Common Stock offered for subscription or purchase in
connection with such rights, options or warrants, and of which the denominator
shall be the number of shares of Common Stock outstanding on the date of
issuance of such rights, options or warrants plus the number of shares which the
aggregate offering price of the total number of shares of Common Stock so
offered would purchase at the current market price per share of Common Stock at
such record date. Such adjustment shall be made whenever such rights, options or
warrants are issued, and shall become effective immediately after the record
date for the determination of stockholders entitled to receive such rights,
options or warrants.

                  (c) In case the Company shall distribute to all holders of its
shares of Common Stock, (including any distribution made in connection with a
merger in which the Company is the surviving corporation), evidences of its
indebtedness or assets (excluding cash, dividends or distributions payable out
of consolidated earnings or earned surplus and dividends or distributions
referred to in paragraph (a) above) or rights, options or warrants, or
convertible or exchangeable securities containing the right to subscribe for or
purchase shares of Common Stock (excluding those re-



                                        9



ferred to in paragraph (b) above), then in each case the number of Warrant
Shares thereafter purchasable upon the exercise of each Warrant shall be
determined by multiplying the number of Warrant Shares theretofore purchasable
upon the exercise of each Warrant by a fraction, of which the numerator shall be
the then current market price per share of Common Stock (as defined in paragraph
(d) below) on the date of such distribution, and of which the denominator shall
be the then current market price per share of Common Stock, less the then fair
value (as determined by the Board of Directors of the Company or, in the case of
Warrants held by the Financial Advisor, an independent investment banker which
shall be mutually agreeable to the parties, whose determination, in each case,
shall be conclusive) of the portion of the assets or evidences of indebtedness
so distributed or of such subscription rights, options or warrants, or of such
convertible or exchangeable securities applicable to one share of Common Stock.
Such adjustment shall be made whenever any such distribution is made, and shall
become effective on the date of distribution retroactive to the record date for
the determination of shareholders entitled to receive such distribution.

                  (d) For the purpose of any computation under paragraphs (b)
and (c) of this Section, the current market price per share of Common Stock at
any date shall be the average of the daily last sale prices for the 20
consecutive trading days ending one trading day prior to the date of such
computation. The closing price for each day shall be the last reported sales
price regular way or, in case no such reported sale takes place on such day, the
average of the closing bid and asked prices regular way for such day, in each
case on the principal national securities exchange on which the shares of Common
Stock are listed or admitted to trading or, if not so listed or admitted to
trading, the last sale price of the Common Stock on NASDAQ or any comparable
system. If the current market price of the Common Stock cannot be so determined,
the Board of Directors of the Company shall reasonably determine the current
market price on the basis of such quotations as are available.

                  (e) No adjustment in the number of Warrant Shares purchasable
hereunder shall be required unless such adjustment would require an increase or
decrease of at least one percent (1%) in the number of Warrant Shares
purchasable upon the exercise of each Warrant; provided, however, that any
adjustments which by reason of this paragraph (e) are not required to be made
shall be carried forward and taken into account in any subsequent adjustment.
All calculations shall be made with respect to the number of Warrant Shares



                                       10


purchasable hereunder, to the nearest tenth of a share and with respect to the
Warrant Price payable hereunder, to the nearest whole cent.

                  (f) Whenever the number of Warrant Shares purchasable upon the
exercise of each Warrant is adjusted, as herein provided, the Warrant Price
payable upon exercise of each Warrant shall be adjusted by multiplying such
Warrant Price immediately prior to such adjustment by a fraction, of which the
numerator shall be the number of Warrant Shares purchasable upon the exercise of
each Warrant immediately prior to such adjustment, and of which the denominator
shall be the number of Warrant Shares purchasable immediately thereafter.

                  (g) No adjustment in the number of Warrant Shares purchasable
upon the exercise of each Warrant need be made under paragraphs (b) and (c) if
the Company issues or distributes to each Holder of Warrants the rights options,
warrants, or convertible or exchangeable securities, or evidences of
indebtedness or assets referred to in those paragraphs which each Holder of
Warrants would have been entitled to receive had the Warrants been exercised
prior to the happening of such event or the record date with respect thereto. No
adjustment need be made for a change in the par value of the Warrant Shares.

                  (h) For the purpose of this subsection 10.1, the term "shares
of Common Stock" shall mean (i) the class of stock designated as the Common
Stock of the Company at the date of this Agreement, or (ii) any other class of
stock resulting from successive changes or reclassifications of such shares
consisting solely of changes in par value, or from par value to no par value, or
from no par value to par value. In the event that at any time, as a result of an
adjustment made pursuant to paragraph (a) above, the Holders shall become
entitled to purchase any securities of the Company other than shares of Common
Stock, thereafter the number of such other shares so purchasable upon exercise
of each Warrant and the Warrant Price of such shares shall be subject to
adjustment from time to time in a manner and on terms as nearly equivalent as
practicable to the provisions with respect to the Warrant Shares contained in
paragraphs (a) through (i), inclusive, and the provisions of Section 5 and
subsections 10.2 through 10.5, inclusive, with respect to the Warrant Shares,
shall apply on like terms to any such other securities.

                  (i)   Upon the expiration of any rights, options, warrants or
 conversion or exchange privileges, if



                                       11


any thereof shall not have been exercised, the Warrant Price and the number of
Warrant Shares purchasable upon the exercise of each Warrant shall, upon such
expiration, be readjusted and shall thereafter be such as it would have been had
it been originally adjusted (or had the original adjustment not been required,
as the case may be) as if (A) the only shares of Common Stock so issued were the
shares of Common Stock, if any, actually issued or sold upon the exercise of
such rights, options, warrants or conversion or exchange rights and (B) such
shares of Common Stock, if any, were issued or sold for the consideration
actually received by the Company upon such exercise plus the aggregate
consideration, if any, actually received by the Company for the issuance, sale
or grant of all such rights, options, warrants or conversion or exchange rights
whether or not exercised.

            10.2 Voluntary Adjustment by the Company. The Company may at its
option, at any time during the term of the Warrants, reduce the then current
Warrant Price to any amount deemed appropriate by the Board of Directors of the
Company.

            10.3 Notice of Adjustment. Whenever the number of Warrant Shares
purchasable upon the exercise of each Warrant or the Warrant Price of such
Warrant Shares is adjusted, as herein provided, the Company shall, or in the
event that a Warrant Agent is appointed, the Company shall cause the Warrant
Agent promptly to, mail by first class, postage prepaid, to each Holder notice
of such adjustment or adjustments. Such notice shall set forth the number of
Warrant Shares purchasable upon the exercise of each Warrant and the Warrant
Price of such Warrant Shares after such adjustment, setting forth a brief
statement of the facts requiring such adjustment and setting forth the
computation by which such adjustment was made.

            10.4 No Adjustment for Dividends. Except as provided in subsection
10.1, no adjustment in respect of any dividends shall be made during the term of
a Warrant or upon the exercise of a Warrant.

            10.5 Preservation of Purchase Rights Upon Merger, Consolidation,
etc. In case of any consolidation of the Company with or merger of the Company
into another corporation or in case of any sale, transfer or lease to another
corporation of all or substantially all the property of the Company, the Company
or such successor or purchasing corporation, as the case may be, shall execute
an agreement that each Holder shall have the right thereafter, upon such



                                       12



Holder's election, either (i) upon payment of the Warrant Price in effect
immediately prior to such action, to purchase upon exercise of each Warrant the
kind and amount of shares and other securities and property (including cash)
which he would have owned or have been entitled to receive after the happening
of such consolidation, merger, sale, transfer or lease had such Warrant been
exercised immediately prior to such action (such shares and other securities and
property (including cash) being referred to as the "Sale Consideration") or (ii)
to receive, in cancellation of such Warrant (and in lieu of paying the Warrant
price and exercising such Warrant), the Sale Consideration less a portion
thereof having a fair market value (as reasonably determined by the Company)
equal to the Warrant Price (it being understood that, if the Sale Consideration
consists of more than one type of shares, other securities or property, the
amount of each type of shares, other securities or property to be received shall
be reduced proportionately); provided, however, that no adjustment in respect of
dividends, interest or other income on or from such shares or other securities
and property shall be made during the term of a Warrant or upon the exercise of
a Warrant. The Company shall mail by first class mail, postage prepaid, to each
Holder, notice of the execution of any such agreement. Such agreement shall
provide for adjustments, which shall be as nearly equivalent as may be
practicable to the adjustments provided for in this Section 10. The provisions
of this subsection 10.5 shall similarly apply to successive consolidations,
mergers, sales, transfers or leases. The Warrant Agent (if appointed) shall be
under no duty or responsibility to determine the correctness of any provisions
contained in any such agreement relating to the kind or amount of shares of
stock or other securities or property receivable upon exercise of Warrants or
with respect to the method employed and provided therein for any adjustments and
shall be entitled to rely upon the provisions contained in any such agreement.
            10.6 Statement on Warrants. Irrespective of any adjustments in the
Warrant Price or the number or kind of shares purchasable upon the exercise of
the Warrants, Warrants issued before or after such adjustment may continue to
express the same price and number and kind of shares as are stated in the
Warrants initially issuable pursuant to this Agreement.

            SECTION 11. Fractional Interests. The Company shall not be required
to issue fractional Warrant Shares on the exercise of Warrants. If more than one
Warrant shall be presented for exercise in full at the same time by the same
Holder, the number of full Warrant Shares which shall be



                                       13



issuable upon the exercise thereof shall be computed on the basis of the
aggregate number of Warrant Shares purchasable on exercise of the Warrants so
presented. If any fraction of a Warrant Share would, except for the provisions
of this Section 11, be issuable on the exercise of any Warrant (or specified
portion thereof), the Company shall pay an amount in cash equal to the average
of the daily closing sale prices (determined in accordance with paragraph (d) of
subsection 10.1) per share of Common Stock for the 20 consecutive trading days
ending one trading day prior to the date the Warrant is presented for exercise,
multiplied by such fraction.

            SECTION 12. No Rights as Shareholders; Notices to Holders. Nothing
contained in this Agreement or in any of the Warrants shall be construed as
conferring upon the Holders or their transferees the right to vote or to receive
dividends or to consent or to receive notice as shareholders in respect of any
meeting of shareholders for the election of directors of the Company or any
other matter, or any rights whatsoever as shareholders of the Company. If,
however, at any time prior to the expiration of the Warrants and prior to their
exercise, any of the following events shall occur:

                  (a) the Company shall declare any dividend payable in any
securities upon its shares of Common Stock or make any distribution (other than
a regular cash dividend, as such dividend may be increased from time to time, or
a dividend payable in shares of Common Stock) to the holders of its shares of
Common Stock; or

                  (b) the Company shall offer to the holders of its shares of
Common Stock on a pro rata basis any cash, additional shares of Common Stock or
other securities of the Company or any right to subscribe for or purchase any
thereof; or

                  (c) a dissolution, liquidation or winding up of the Company
(other than in connection with a consolidation, merger, sale, transfer or lease
of all or substantially all of its property, assets, and business as an
entirety) shall be proposed,

then in any one or more of said events the Company shall (a) give notice in
writing of such event as provided in Section 14 hereof and (b) if the Warrants
have been registered pursuant to the Securities Act of 1933, cause notice of
such event to be published once in The Wall Street Journal (national edition),
such giving of notice and publication to



                                       14



be completed at least 10 days prior to the date fixed as a record date or the
date of closing the transfer books for the determination of the stockholders
entitled to such dividend, distribution, or subscription rights or for the
determination of stockholders entitled to vote on such proposed dissolution,
liquidation or winding up or the date of expiration of such offer. Such notice
shall specify such record date or the date of closing the transfer books or the
date of expiration, as the case may be. Failure to publish, mail or receive such
notice or any defect therein or in the publication or mailing thereof shall not
affect the validity of any action in connection with such dividend, distribution
or subscription rights, or such proposed dissolution, liquidation or winding up,
or such offer.

            SECTION 13. Appointment of Warrant Agent. At such time as the
Company shall register Warrants under the Securities Act of 1933, the Company
shall appoint a Warrant Agent to act on behalf of the Company in connection with
the issuance, division, transfer and exercise of Warrants. At such time as the
Company appoints a Warrant Agent, the Company shall enter into a new Warrant
Agreement with the Warrant Agent pursuant to which all new Warrants will be
issued, which will reflect the appointment of the Warrant Agent, as well as
additional customary provisions as shall be reasonably requested by the Warrant
Agent in connection with the performance of its duties. In the event that a
Warrant Agent is appointed, the Company shall (i) promptly notify the Holders of
such appointment and the place designated for transfer, exchange and exercise of
the Warrants, and (ii) take such steps as are necessary to insure that Warrants
issued prior to such appointment may be exchanged for Warrants countersigned by
the Warrant Agent.

            SECTION 14. Notices; Principal Office. Any notice pursuant to this
Agreement by the Company or by any Holder to the Warrant Agent (if so
appointed), or by the Warrant Agent (if so appointed) or by any Holder to the
Company, shall be in writing and shall be delivered in person, or mailed first
class, postage prepaid (a) to the Company, at its office, Attention: President
or (b) to the Warrant Agent, at its offices as designated at the time the
Warrant Agent is appointed. The address of the principal office of the Company
is 935 Pardee Street, Berkeley, California 94710. Each party hereto may from
time to time change the address to which notices to it are to be delivered or
mailed hereunder by notice to the other party.

            Any notice mailed pursuant to this Agreement by
the Company or the Warrant Agent to the Holders shall be in



                                       15




writing and shall be mailed first class, postage prepaid, or otherwise
delivered, to such Holders at their respective addresses on the books of the
Company or the Warrant Agent, as the case may be.

            SECTION 15. Successors. Except as expressly provided herein to the
contrary, all the covenants and provisions of this Agreement by or for the
benefit of the Company and the Financial Advisor shall bind and inure to the
benefit of their respective successors and permitted assigns hereunder.

            SECTION 16. Merger or Consolidation of the Company. The Company will
not merge or consolidate with or into, or sell, transfer or lease all or
substantially all of its property to, any other corporation unless the successor
or purchasing corporation, as the case may be (if not the Company), shall
expressly assume, by supplemental agreement, the due and punctual performance
and observance of each and every covenant and condition of this Agreement to be
performed and observed by the Company.

            SECTION 17. Legends. The Warrants issued pursuant to this Agreement
shall bear an appropriate legend, conspicuously disclosing the restrictions on
exercise and transfer under Section 2.2 of this Agreement.

            SECTION 18. Applicable Law. This Agreement and each Warrant issued
hereunder shall be governed by and construed in accordance with the laws of the
State of California, without giving effect to principles of conflict of laws.

            SECTION 19. Benefits of this Agreement. Nothing in this Agreement
shall be construed to give to any person or corporation other than the Company,
the Warrant Agent (if appointed) and the Holders any legal or equitable right,
remedy or claim under this Agreement; but this Agreement shall be for the sole
and exclusive benefit of the Company, the Warrant Agent and the Holders of the
Warrants.

            SECTION 20. Counterparts. This Agreement may be executed in any
number of counterparts and each of such counterparts shall for all purposes be
deemed to be an original, and all such counterparts shall together constitute
but one and the same instrument.

            SECTION 21. Captions. The captions of the Sections and subsections
of this Agreement have been



                                       16



inserted for convenience only and shall have no substantive effect.


            IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be duly executed, all as of the day and year first above written.


                                       BIOTIME, INC.


                                       By: /s/ Paul Segall, Ph.D
                                       Name: Paul Segall, Ph.D
                                       Title: President and Chief
                                                Executive Officer


Attest:


By: /s/ Judith Segall
   Name: Judith Segall
   Title: Secretary


                                       GREENBELT CORP.


                                       By: /s/ Alfred D. Kingsley
                                       Name: Alfred D. Kingsley
                                       Title: President

Attest:


By: /s/ Gary K. Duberstein
Name: Gary K. Duberstein
Title: Vice President




                                       17


                                                                       EXHIBIT A


            THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
1933, AS AMENDED, OR UNDER APPLICABLE STATE SECURITIES LAWS. THIS WARRANT MAY
NOT BE EXERCISED, SOLD, PLEDGED, HYPOTHECATED, TRANSFERRED OR ASSIGNED EXCEPT
UNDER AN EFFECTIVE REGISTRATION STATEMENT UNDER SUCH ACT AND APPLICABLE STATE
SECURITIES LAWS, UNLESS AN EXEMPTION FROM SUCH REGISTRATION IS AVAILABLE AND THE
HOLDER SHALL HAVE DELIVERED AN OPINION OF COUNSEL ADDRESSED TO THE COMPANY TO
SUCH EFFECT; PROVIDED, THAT SUCH OPINION SHALL BE IN FORM AND SUBSTANCE AND FROM
COUNSEL REASONABLY SATISFACTORY TO THE COMPANY.

VOID AFTER 5:00 P.M. NEW YORK TIME, [INSERT EXPIRATION DATE]


Certificate No.________                             Warrant to Purchase
                                               [Insert number of Shares]
                                               -------------------------
Shares of Common Stock


                                  BIOTIME, INC.
                         COMMON SHARE PURCHASE WARRANTS

            This certifies that, for value received, [Insert name of Holder] or
registered assigns (the "Holder"), is entitled to purchase from Biotime, Inc. a
California corporation (the "Company"), at any time after 9:00 A.M., New York
time, on [Insert Date of Allowed Exercise pursuant to Section 1 of the Warrant
Agreement referred to below] at a purchase price per share [Insert Warrant Price
determined pursuant to Sections 9 and 10 of the Warrant Agreement] (the "Warrant
Price"), the number of its Common Shares, no par value per share (the "Common
Stock"), shown above. The number of shares purchasable upon exercise of the
Common Share Purchase Warrants (the "Warrants") and the Warrant Price are
subject to adjustment from time to time as set forth in the Warrant Agreement
referred to below. Outstanding Warrants not exercised prior to 5:00 p.m., New
York time, on [Insert Expiration Date pursuant to Section 1 of the Warrant
Agreement] shall thereafter be void.

            Subject to restriction specified in the Warrant Agreement, Warrants
may be exercised in whole or in part by presentation of this Warrant Certificate
with the Purchase Form on the reverse side hereof duly executed, which signature
shall be guaranteed by a bank or trust company or a broker or dealer which is a
member of the National



                                       18



Association of Securities Dealers, Inc., and simultaneous payment of the Warrant
Price (or as otherwise set forth in Section 10.5) of the Warrant Agreement at
the principal office of the Company (or if a Warrant Agent is appointed, at the
principal office of the Warrant Agent). Payment of such price shall be made in
cash or by certified or bank cashier's check. As provided in the Warrant
Agreement, the Warrant Price and the number or kind of shares which may be
purchased upon the exercise of the Warrant evidenced by this Warrant Certificate
are, upon the happening of certain events, subject to modification and
adjustment.

            This Warrant Certificate is issued under and in accordance with a
Warrant Agreement dated as of September 13, 1995 between the Company and
Greenbelt Corp. and is subject to the terms and provisions contained in the
Warrant Agreement, to all of which the Holder of this Warrant Certificate by
acceptance of this Warrant Certificate consents. A copy of the Warrant Agreement
may be obtained by the Holder hereof upon written request to the Company. In the
event that pursuant to Section 13 of the Warrant Agreement a Warrant Agent is
appointed and a new warrant agreement entered into between the Company and such
Warrant Agent, then such new warrant agreement shall constitute the Warrant
Agreement for purposes hereof and this Warrant Certificate shall be deemed to
have been issued pursuant to such new warrant agreement.

            Upon any partial exercise of the Warrant evidenced by this Warrant
Certificate, there shall be issued to the Holder hereof a new Warrant
Certificate in respect of the shares of Common Stock as to which the Warrant
evidenced by this Warrant Certificate shall not have been exercised. This
Warrant Certificate may be exchanged at the office of the Company (or the
Warrant Agent, if appointed) by surrender of this Warrant Certificate properly
endorsed either separately or in combination with one or more other Warrant
Certificates for one or more new Warrant Certificates evidencing the right of
the Holder thereof to purchase the aggregate number of shares as were
purchasable on exercise of the Warrants evidenced by the Warrant Certificate or
Certificates exchanged. No fractional shares will be issued upon the exercise of
any Warrant, but the Company will pay the cash value thereof determined as
provided in the Warrant Agreement. This Warrant Certificate is transferable at
the office of the Company (or the Warrant Agent, if appointed) in the manner and
subject to the limitations set forth in the Warrant Agreement.




                                       19



            The Holder hereof may be treated by the Company, the Warrant Agent
(if appointed) and all other persons dealing with this Warrant Certificate as
the absolute owner hereof for any purpose and as the person entitled to exercise
the rights represented hereby, or to the transfer hereof on the books of the
Company, any notice to the contrary notwithstanding, and until such transfer on
such books, the Company (and the Warrant Agent, if appointed) may treat the
Holder hereof as the owner for all purposes.

            Neither the Warrant nor this Warrant Certificate entitles any Holder
to any of the rights of a stockholder of the Company.

            [This Warrant Certificate shall not be valid or obligatory for any
purpose until it shall have been countersigned by the Warrant Agent.]*

DATED:

                                    BIOTIME, INC.


(Seal)                              By:________________________

                                    Title:_____________________

                                    Attest:____________________

[COUNTERSIGNED:

________________________,
WARRANT AGENT


By:_________________________]*
      Authorized Signature

- --------------------

*     To be part of the Warrant only after the appointment of a Warrant Agent
      pursuant to Section 13 of the Warrant Agreement.



                                       20


                                  PURCHASE FORM

                  (To be executed upon exercise of Warrant)



To Biotime, Inc.:

            The undersigned hereby irrevocably elects to exercise the right of
purchase represented by the within Warrant Certificate for, and to purchase
thereunder, _____ shares of Common Stock, as provided for therein, and tenders
herewith payment of the purchase price in full in the form of cash or a
certified or bank cashier's check in the amount of $_________.

            Please issue a certificate or certificates for such shares of Common
Stock in the name of, and pay any cash for any fractional share to:


PLEASE INSERT SOCIAL SECURITY             NAME ______________________________
OR OTHER IDENTIFYING NUMBER               (Please Print Name &
OF ASSIGNEE                                  Address)


___________________________               Address ___________________________

___________________________               Signature _________________________
                                          NOTE:    The above signature
                                                   should correspond exactly
                                                   with the name on the face of
                                                   this Warrant Certificate or
                                                   with the name of the assignee
                                                   appearing in the assignment
                                                   form below.

And, if said number of shares shall not be all the shares purchasable under the
within Warrant Certificate, a new Warrant Certificate is to be issued in the
name of said undersigned for the balance remaining of the share purchasable
thereunder less any fraction of a share paid in cash.



                                       21



                                   ASSIGNMENT

        (To be executed only upon assignment of Warrant Certificate)

            For value received, _____________ hereby sells, assigns and
transfers unto _______________ the within Warrant Certificate, together with all
right, title and interest therein, and does hereby irrevocably constitute and
appoint _________________ attorney, to transfer said Warrant Certificate on the
books of the within-named Company, with full power of substitution in the
premises.


Dated:___________________                 ____________________________
                                          NOTE:    The above signature
                                                   should correspond
                                                   exactly with the name
                                                   on the face of this
                                                   Warrant Certificate.





                                       22