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                                                                Exhibit 10.20

                                  BIONEBRASKA, INC.
                         NON-QUALIFIED STOCK OPTION AGREEMENT

       THIS OPTION AGREEMENT is made as of the _____ day of _______________,
1993, between BioNebraska, Inc., a Delaware corporation (the "Company"), and
________________________________________, a consultant to the Company (the
"Optionee").

       The Company desires, by affording the Optionee an opportunity to purchase
shares of its Common Stock, of the par value of One Cent ($.01) per share (the
"Common Stock"), as hereinafter provided, to carry out the purpose of the 1993
Stock Plan of the Company, as amended (the "Plan").

       THEREFORE, the parties hereby agree as follows:

       1.     GRANT OF OPTION.  The Company hereby grants to the Optionee the
right and option (hereinafter called the "Option") to purchase from the Company
all or any part of an aggregate amount of _______________ shares of the Common
Stock of the Company on the terms and conditions herein set forth.

       2.     PURCHASE PRICE.  The purchase price of the shares of the Common
Stock covered by this Option shall be $__________ per share.

       3.     TERM OF OPTION.  The term of the Option shall be for a period of
[FIVE (5)] years from the date hereof (the "Option Date"), subject to earlier
termination as hereinafter provided.

       4.     EXERCISE OF OPTION.  During the first year the Option is
outstanding, it may not be exercised with respect to any of the Shares covered
hereby.  Thereafter, subject to the terms and conditions hereby, the Option may
be exercised as follows:

              (a)    From and after 12 months from the Option Date, the Option
       may be exercised as to _____ shares.

              (b)    From and after 24 months from the Option Date, the Option
       may be exercised as to an additional _____ shares.

              (c)    From and after 36 months from the Option Date, the Option
       may be exercised as to an additional _____ shares.

              5.     CHANGE OF CONTROL.  Upon a Change of Control, each
outstanding Stock Option shall become exercisable in full as to all of the
shares covered thereby without regard to


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any installment exercise or vesting provisions.  For purposes of this
Section 5, the term "Change of Control" means any of the following:

              (a)    any "person" (as such term is used in Sections 13(d) and
       14(d) of the Securities Exchange Act of 1934) becomes a "beneficial
       owner" (as defined in Rule 13d-3 under the Exchange Act), directly or
       indirectly, of securities of the Company representing 50% or more of the
       combined voting power of the Company's then outstanding securities; or

              (b)    a business combination, following which shareholders of the
       Company do not continue to beneficially own at least 50% of the voting
       power of the resulting entity or the members of the Company's Board of
       Directors prior to the transaction do not constitute a majority of the
       resulting entity's Board of Directors; or

              (c)    A liquidation, dissolution or sale of all or substantially
       all of the assets of the Company, and immediately thereafter, there is no
       substantial continuity of ownership with respect to the Company and the
       entity to which such assets have been transferred.

       The grant of an option pursuant to the Plan shall not limit in any way
the right or power of the Company to make adjustments, reclassifications,
reorganizations or changes of its capital or business structure or to merge,
exchange or consolidate or to dissolve, liquidate, sell or transfer all or any
part of its business or assets.

       6.     NON-TRANSFERABILITY.  The Option shall not be transferable
otherwise than by will or the laws of descent and distribution, and the Option
may be exercised, during the lifetime of the Optionee, only by the Optionee.

       7.     TERMINATION OF CONSULTING RELATIONSHIP.  If the Optionee's service
as a consultant to the Company shall terminate by reason of death, the Option
may be exercised, to the extent that the Optionee shall have been entitled to do
so at the date of such termination by reason of death, by his or her legal
representative or by the person to whom the Option is transferred by will or the
applicable laws of descent and distribution at any time within one hundred
eighty (180) days after the termination of Optionee's consulting relationship
with the Company, but in no event later than the expiration of the term
specified in Section 3 hereof.

       8.     OTHER TERMINATION.  In the event the Optionee's service as a
consultant to the Company shall terminate for any reason other than death, any
unexercised Option may be exercised by the Optionee at any time within one
hundred twenty (120) days of such termination but only to the extent the Option
was exercisable by the Optionee on the date of termination.  In no event shall
any Option be exercisable after the expiration of the term specified in
Section 3 hereof.


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       9.     METHOD OF EXERCISING OPTION.  Subject to the terms and conditions
of this Option Agreement, the Option may be exercised by written notice to the
Company at the principal office of the Company.  Such notice shall state the
election to exercise the Option and the number of shares in respect of which it
is being exercised, and shall be signed by the person so exercising the Option.
Such notice shall be accompanied by payment of the full purchase price of such
shares, which payment shall be made by check or bank draft payable to the
Company, or, in the discretion of the Company, by delivery of shares of Common
Stock of the Company with a fair market value equal to the purchase price or by
a combination of cash and such shares, whose fair market value shall equal the
purchase price.  For purposes of this paragraph, the "fair market value" of the
Common Stock of the Company shall be established in the manner set forth in the
Plan.  In the event the Option shall be exercised by any person other than the
Optionee, such notice shall be accompanied by appropriate proof of such right of
such person to exercise the Option.

       10.    OPTION PLAN.  This Option is subject to certain additional terms
and conditions set forth in the Plan pursuant to which this Option has been
issued.  A copy of the Plan is on file with the Treasurer of the Company, and by
acceptance hereof, Optionee agrees to and accepts this Option subject to the
terms of the Plan.  Except as otherwise defined herein, defined terms used in
this Agreement shall have the meaning ascribed thereto in the Plan.

       11.    DISPUTES.  As a condition of the granting of the Option herein
granted, the Optionee agrees, for the Optionee and the Optionee's personal
representatives, that any dispute or disagreement which may arise under or as a
result of or pursuant to this Agreement shall be determined by the Compensation
Committee of the Board of Directors of the Company, or the Board if there is no
such committee, in its sole discretion, and that any interpretation by said
Committee of the terms of this Agreement shall be final, binding and conclusive.

       12.    BINDING EFFECT.  This Agreement shall be binding upon the heirs,
executors, administrators and successors of the parties hereto.

       IN WITNESS WHEREOF, the Company and the Optionee have executed this
Agreement as of the date and year first above written.

                                          BIONEBRASKA, INC.



                                          By_________________________________
                                               Chairman of the Board and CEO


                                          ____________________________________
                                          Optionee


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