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                                                                   Exhibit 10.18

                                                                      APPENDIX B

                                  WARRANT NO. ______
                          WARRANT FOR PURCHASE OF SHARES OF
                                     COMMON STOCK
                                 OF BIONEBRASKA, INC.
                                 ______________, 1997


       FOR VALUE RECEIVED, ______________________, or registered assigns (the
"Holder"), is entitled to purchase from BioNebraska, Inc., a Delaware
corporation (the "Company"), commencing on the maturity date, including any
extensions (the "Maturity Date") of the Subordinated Promissory Note issued by
the Company to the Holder pursuant to the Agreement referred to below (the
"Note"), and continuing until the fifth anniversary of the date of the original
issuance of this Warrant, __________ fully paid and nonassessable shares of the
Company's Common Stock, par value $.01 per share, (such class of stock being
hereinafter referred to as the "Common Stock" and such Common Stock as may be
acquired upon exercise hereof being hereinafter referred to as the "Warrant
Stock"), at an exercise price (the " Warrant Exercise Price") equal to (a)
eighty percent (80%) of the price to public of  initial public offering of the
Company's Common Stock which is effective on or before the Maturity Date, or (b)
$7.00 per share, in the event such public offering is not completed or is
completed after the Maturity Date.

       The Warrant has been issued to the Holder by the Company pursuant to the
Bridge Loan Agreement dated  of __________, 1997, by and between the Company and
the Holder (the "Agreement"), and is subject to the terms and provisions
thereof.

       This Warrant is subject to the following provisions, terms, and
conditions:

       1.   The rights represented by this Warrant may be exercised by the
Holder, in whole or in part (but not  to a fractional share of Common Stock),
by written notice of exercise substantially in the form attached hereto as
Schedule I, which notice shall be delivered to the Company accompanied by the
surrender of this Warrant (properly endorsed if required) at the principal
office of the Company and upon payment to the Company, by cash, certified
check or bank draft, of the Warrant Exercise Price for such shares.  The
Company agrees that the Warrant Stock so purchased shall be and is deemed to
be issued as of the close of business on the date on which this Warrant shall
have been surrendered and payment made for such Warrant Stock as aforesaid.
Certificates for the shares of Warrant Stock so purchased shall be delivered
to the Holder within thirty (30) days after the rights represented by this
Warrant shall have been so exercised, and, unless this Warrant has expired, a
new Warrant representing the number of shares of Warrant  Stock, if any, with
respect to which this Warrant has not been exercised shall also be delivered
to the Holder within such time. Notwithstanding the foregoing, however, the
Company shall not be required to deliver any certificates for shares of
Warrant Stock, except in accordance


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with the provisions and subject to the limitations of Paragraph 5 below.

       2.     The Company covenants and agrees that all shares of Warrant Stock
that may be issued upon the exercise of this Warrant will, upon issuance, be
duly authorized and issued, fully paid and nonassessable and free from all
taxes, liens, and charges with respect to the issuance thereof.  The Company
further covenants and agrees that until expiration of this Warrant, the
Company will at all times have authorized, and reserved for the purpose of
issuance upon exercise of this Warrant, a sufficient number of shares of
Common Stock to provide for the exercise of this Warrant.

       3.     The provisions in this Warrant relating to the Warrant Exercise
Price and the number of shares of Warrant Stock to be issued upon exercise of
this Warrant shall be subject to adjustment from time to time as hereinafter
provided.

              (a)    Upon each adjustment of the Warrant Exercise Price, the
       Holder of this Warrant shall thereafter be entitled to purchase, at the
       Warrant Exercise Price resulting from such adjustment, the number of
       shares of Common Stock obtained by multiplying the Warrant Exercise Price
       in effect immediately prior to such adjustment by the number of shares of
       Common Stock purchasable hereto immediately prior to such adjustment and
       dividing the product thereof by the Warrant Exercise Price resulting from
       such adjustment.

              (b)    In case the Company shall at any time subdivide its
       outstanding Common Stock into a greater number of shares or declare a
       dividend payable in Common Stock, the Warrant Exercise Price in effect
       immediately prior to such subdivision shall be proportionately reduced
       and the number of shares of Common Stock purchasable pursuant to this
       Warrant shall be proportionately increased, and conversely, in case the
       Company's outstanding Common Stock shall be combined into a smaller
       number of shares, the Warrant  Exercise Price in effect immediately prior
       to such combination shall be proportionately increased and the number of
       shares of Common Stock purchasable upon the exercise of this Warrant
       shall be proportionately reduced.

              (c)    If any capital reorganization or reclassification of the
       capital stock of the Company, or consolidation or merger of the Company
       with another corporation, or the sale of all or substantially all of its
       assets to another corporation shall be effected in such a way that
       holders of Common Stock shall be entitled to receive stock, securities or
       assets ("Substituted Property") with respect to or in exchange for such
       Common Stock, then, a condition of such reorganization, reclassification,
       consolidation, merger or sale, the Holder shall have the right to
       purchase and receive upon the basis and upon the terms and conditions
       specified in this Warrant, and in lieu of the Common Stock of the Company
       immediately theretofore purchasable and receivable upon the exercise of
       the rights represented hereby, such Substituted Property as would have
       been issued or delivered to the Holder if it had exercised this Warrant
       and had received upon exercise of this Warrant


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       the Common Stock prior to such reorganization, reclassification,
       consolidation, merger, or sale. The Company shall not effect any such
       consolidation, merger, or sale, unless prior to the consummation
       thereof the successor corporation (if other than the Company)
       resulting from such consolidation or merger or the corporation
       purchasing such assets shall assume by written instrument executed
       and mailed to the Holder at the last address of the Holder appearing
       on the books of the Company, the obligation to deliver to the Holder
       such Substituted Property, in accordance with the foregoing
       provisions, the Holder may be entitled to purchase.

              (d)    If the Company takes any other action, or if any other
       event occurs which does not come within the scope of the provisions of
       Paragraphs 3 (b) or 3 (c), but which should result in an adjustment in
       the Warrant Exercise Price and/or the number of shares subject to the
       Warrant in order to fairly protect the purchase rights of the Holder, an
       appropriate adjustment in such purchase rights shall be made by the
       Company.

              (e)    Upon any adjustment of the Warrant Exercise Price or the
       number of shares issuable upon exercise of this Warrant, the Company
       shall have written notice thereof, by first-class mail, postage prepaid,
       addressed to the Holder at the address of the Holder and shown on the
       books of the Company, which notice shall state the Warrant Exercise Price
       resulting from such adjustment and the increase or decrease, if any, in
       the number of shares purchasable at such price upon the exercise of this
       Warrant, setting forth in reasonable detail the method of calculation and
       the facts upon which such calculation is based.

       4.     This Warrant shall not entitle the Holder to any voting rights
or other rights as a shareholder of the Company.

       5.     The Holder, by acceptance hereof, represents and warrants that
(a) it is acquiring this Warrant for its own account for investment purposes
only and not with a view to its resale or distribution and (b) it has no
present intention to resell or otherwise dispose of all or any part of this
Warrant.  Other than pursuant to registration under federal and applicable
state securities laws or exemption from such registration, the availability
of which the Company shall determine in its sole discretion, neither this
Warrant nor any shares of Warrant Stock may be sold, pledged, assigned, or
otherwise disposed of (whether voluntarily or involuntarily).  Company may
condition such sale, pledge, assignment, or other disposition on the receipt
from the party to whom this Warrant is to be so transferred or to whom
Warrant Stock is to be issued or so transferred of any representations and
agreements requested by the Company in order to permit such issuance or
transfer to be made pursuant to exemptions from registration under federal
and applicable state securities laws.  Each certificate representing the
Warrant (or any part thereof) and any shares of Warrant Stock shall bear
appropriate legends setting forth these restrictions on transferability.  The
Holder, by acceptance hereof, agrees to give written notice to the Company
before transferring this Warrant or any shares of Warrant Stock of the
Holder's intention to do so, describing briefly the manner of any proposed
transfer.  Within thirty (30) days after receiving


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such written notice, the Company shall notify the Holder to whether such
transfer may be effected and of the conditions to any such transfer.

       6.   This Warrant shall be transferable only on the books of the
Company by the Holder in person, or by duly authorized attorney, on surrender
of the Warrant, properly assigned.

       7.   Neither this Warrant nor any terms hereof may be changed, waived,
discharged, or terminated orally but only by an instrument in writing signed
by the party against which enforcement of the change, waiver, discharge, or
termination is sought.

       IN WITNESS WHEREOF, the Company has caused this Warrant to be executed on
its behalf by its duly authorized officer on the day and year first above
written.

                                          BIONEBRASKA, INC.


                                          By __________________________________
                                                 Its __________________________