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                                                                    Exhibit 10.1

                                                                      As Amended
                                                                   July 21, 1998

                                BIONEBRASKA, INC.
                                 1993 STOCK PLAN

         SECTION 1.  GENERAL PURPOSE OF PLAN; DEFINITIONS.


         The name of this plan is the BioNebraska, Inc. 1993 Stock Plan (the
"Plan"). The purpose of the Plan is to enable BioNebraska, Inc. (the "Company")
and its Subsidiaries to retain and attract executives, key employees (whether
full or part-time), consultants and non-employee directors who contribute to the
Company's success by their ability, ingenuity and industry, and to enable such
individuals to participate in the long-term success and growth of the Company by
giving them a proprietary interest in the Company.

         For purposes of the Plan, the following terms shall be defined as set
forth below:

         a.       "BOARD" means the Board of Directors of the Company.

         b.       "CAUSE" means a felony conviction of a participant, the
                  failure of a participant to contest prosecution for a felony,
                  or a participant's willful misconduct or dishonesty which is
                  materially harmful to the business or reputation of the
                  Company.

         c.       "CODE" means the Internal Revenue Code of 1986, as amended.

         d.       "COMMITTEE" means the Committee referred to in Section 2 of
                  the Plan. If at any time no Committee shall be in office, then
                  the functions of the Committee specified in the Plan shall be
                  exercised by the Board.

         e.       "COMPANY" means BioNebraska, Inc., a corporation organized
                  under the laws of the State of Delaware (or any successor
                  corporation).

         f.       "DISABILITY" means permanent and total disability as
                  determined by the Committee.

         g.       "DISINTERESTED PERSON" shall have the meaning set forth in
                  Rule 16b-3 as promulgated by the Securities and Exchange
                  Commission under the Securities Exchange Act of 1934, or any
                  successor definition adopted by the Commission.

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         h.       "EARLY RETIREMENT" means retirement, with consent of the
                  Committee at the time of retirement, from active employment
                  with the Company and any Subsidiary or Parent Corporation of
                  the Company.

         i.       "FAIR MARKET VALUE" means the value of the Stock on a given
                  date as determined by the Committee in accordance with the
                  applicable Treasury Department regulations under Section 422
                  of the Code with respect to "incentive stock options."

         j.       "INCENTIVE STOCK OPTION" means any Stock Option intended to be
                  and designated as an "Incentive Stock Option" within the
                  meaning of Section 422 of the Code.

         k.       "NON-QUALIFIED STOCK OPTION" means any Stock Option that is
                  not an Incentive Stock Option, and is intended to be and is
                  designated as a "Non-Qualified Stock Option."

         l.       "NON-EMPLOYEE DIRECTOR" means any member of the Board who is
                  not an employee of the Company, any Parent Corporation or
                  Subsidiary.

         m.       "NORMAL RETIREMENT" means retirement from active employment
                  with the Company, any Subsidiary or Parent Corporation of the
                  Company on or after age 65.

         n.       "PARENT CORPORATION" means any corporation (other than the
                  Company) in an unbroken chain of corporations ending with the
                  Company if each of the corporations (other than the Company)
                  owns stock possessing 50% or more of the total combined voting
                  power of all classes of stock in one of the other corporations
                  in the chain.

         o.       "RETIREMENT" means Normal Retirement or Early Retirement.

         p.       "STOCK" means the Common Stock, $.01 par value per share,
                  of the Company.

         q.       "STOCK OPTION" means any option to purchase shares of Stock
                  granted pursuant to Section 5 below.

         r.       "SUBSIDIARY" means any corporation (other than the Company) in
                  an unbroken chain of corporations beginning with the Company
                  if each of the corporations (other than the last corporation
                  in the unbroken chain) owns stock possessing 50% or more of
                  the total combined voting power of all classes of stock in one
                  of the other corporations in the chain.


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         SECTION 2.  ADMINISTRATION.

         The Plan shall be administered by the Board of Directors or by a
Committee of not less than two directors, all of whom are Disinterested Persons,
who shall be appointed by the Board of Directors of the Company and who shall
serve at the pleasure of the Board.

         The Committee shall have the power and authority to grant Stock Options
to eligible persons, pursuant to the terms of this Plan. In particular, the
Committee shall have the authority:

                  (i)      to select the officers and other key employees of the
                           Company or its Subsidiaries, and consultants and
                           other persons having a contractual relationship with
                           the Company or its Subsidiaries, to whom Stock
                           Options may from time to time be granted hereunder;

                  (ii)     to determine whether and to what extent Incentive
                           Stock Options or Non-Qualified Stock Options, or a
                           combination thereof, are to be granted hereunder;

                  (iii)    to determine the number of shares to be covered by
                           each such award granted hereunder;

                  (iv)     to determine the terms and conditions, not
                           inconsistent with the terms of the Plan, of any award
                           granted hereunder (including, but not limited to, any
                           restriction on any Stock Option and/or the shares of
                           Stock relating thereto) and to amend such terms and
                           conditions (including, but not limited to, any
                           amendment which accelerates the vesting of any
                           award); and

                  (v)      to determine whether, to what extent, and under what
                           circumstances, Stock Options may be exercised
                           following termination of employment.

         The Committee shall have the authority to adopt, alter and repeal such
administrative rules, guidelines and practices governing the Plan as it shall,
from time to time, deem advisable; to interpret the terms and provisions of the
Plan and any award issued under the Plan (and any agreements relating thereto);
and to otherwise supervise the administration of the Plan. The Committee may
delegate its authority to the President and/or the Chief Executive Officer of
the Company for the purpose of selecting employees who are not officers of the
Company for purposes of (i) above.

         All decisions made by the Committee pursuant to the provisions of the
Plan shall be final and binding on all persons, including the Company and Plan
participants.


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         SECTION 3.  STOCK SUBJECT TO PLAN.

         The total number of shares of Stock reserved and available for
distribution under the Plan shall be 1,500,000 shares, subject to increase or
decrease in the event of any adjustment required in the paragraph below. Such
shares may consist, in whole or in part, of authorized and unissued shares. If
any shares that have been optioned cease to be subject to Options, are forfeited
or such award otherwise terminates without a payment being made to the
participant, such shares shall again be available for distribution in connection
with future awards under the Plan.

         In the event of any merger, reorganization, consolidation,
recapitalization, stock dividend, stock split (reverse or other), other change
in corporate structure affecting the Stock, or spinoff or other distribution of
assets to stockholders, such substitution or adjustment shall be made in the
aggregate number of shares reserved for issuance under the Plan and in the
number and option price of shares subject to outstanding options granted under
the Plan as may be determined to be appropriate by the Committee, in its sole
discretion, provided that the number of shares subject to any award shall always
be a whole number.

         SECTION 4.  ELIGIBILITY.

         Officers, other employees of the Company or its Subsidiaries,
Non-Employee Directors, consultants and other persons having a contractual
relationship with the Company or its Subsidiaries who are responsible for or
contribute to the management, growth and/or profitability of the business of the
Company and its Subsidiaries are eligible to be granted Stock Options under the
Plan. The optionees under the Plan shall be selected from time to time by the
Committee, in its sole discretion, from among those eligible, and the Committee
shall determine, in its sole discretion, the number of shares covered by each
award.

         SECTION 5.  STOCK OPTIONS.

         Any Stock Option granted under the Plan shall be in such form as the
Committee may from time to time approve.

       The Stock Options granted under the Plan may be of two types: (i)
Incentive Stock Options and (ii) Non-Qualified Stock Options. No Incentive Stock
Options shall be granted under the Plan after June 26, 2008.(1)

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         (1) As a result of the Board of Directors approval of the increase
in number of shares reserved for issuance of the Plan on June 26, 1998 (which
was approved by the Shareholders on July 21, 1998), this date has been
extended from June 29, 2003 to June 26, 2008.


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         The Committee shall have the authority to grant any optionee Incentive
Stock Options, Non-Qualified Stock Options, or both types of options. To the
extent that any option does not qualify as an Incentive Stock Option, it shall
constitute a separate Non-Qualified Stock Option.

         Anything in the Plan to the contrary notwithstanding, no term of this
Plan relating to Incentive Stock Options shall be interpreted, amended or
altered, nor shall any discretion or authority granted under the Plan be so
exercised, so as to disqualify either the Plan or any Incentive Stock Option
under Section 422 of the Code. The preceding sentence shall not preclude any
modification or amendment to an outstanding Incentive Stock Option, whether or
not such modification or amendment results in disqualification of such Option as
an Incentive Stock Option, provided the optionee consents in writing to the
modification or amendment.

         Options granted under the Plan shall be subject to the following terms
and conditions and shall contain such additional terms and conditions, not
inconsistent with the terms of the Plan, as the Committee shall deem desirable.

         (a) OPTION PRICE. The option price per share of Stock purchasable under
a Stock Option shall be determined by the Committee at the time of grant. In no
event shall the option price per share of Stock purchasable under an Incentive
Stock Option be less than 100% of the Fair Market Value of the Stock on the date
of the grant of the option. If an employee owns or is deemed to own (by reason
of the attribution rules applicable under Section 424(d) of the Code) more than
10% of the combined voting power of all classes of stock of the Company or any
Parent Corporation or Subsidiary and an Incentive Stock Option is granted to
such employee, the option price shall be no less than 110% of the Fair Market
Value of the Stock on the date the option is granted.

         (b) OPTION TERM. The term of each Stock Option shall be fixed by the
Committee, but no Incentive Stock Option shall be exercisable more than ten
years after the date the option is granted. If an employee owns or is deemed to
own (by reason of the attribution rules of Section 425(4) of the Code) more than
10% of the combined voting power of all classes of stock of the Company or any
Parent Corporation or Subsidiary and an Incentive Stock Option is granted to
such employee, the term of such option shall be no more than five years from the
date of grant.

         (c) EXERCISABILITY. Stock Options shall be exercisable at such time or
times as determined by the Committee, in its discretion, at or after grant. If
the Option is exercisable in installments, the Committee may waive such
installment exercise provisions at any time. Installment exercise restrictions
may be based upon the lapse of time, the attainment of specified performance
goals, or a combination of each. Notwithstanding the foregoing, unless the Stock
Option Agreement provides otherwise, any Stock Option granted under this Plan
shall be exercisable in full, without regard to any installment exercise
provisions, for a period specified by the Company, but not to exceed sixty (60)
days, prior to the occurrence of any of the following events: (i) dissolution or
liquidation of the Company other than in conjunction with a bankruptcy of the
Company or any similar occurrence, (ii) any merger, consolidation,


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acquisition, separation, reorganization, or similar occurrence, where the
Company will not be the surviving entity or (iii) the transfer of
substantially all of the assets of the Company or 75% or more of the
outstanding Stock of the Company.

         (d) METHOD OF EXERCISE. Stock Options may be exercised to the extent
the Options are vested at any time during the option period by giving written
notice of exercise to the Company specifying the number of shares to be
purchased. Such notice shall be accompanied by payment in full of the purchase
price, either by certified or bank check, or by any other form of legal
consideration deemed sufficient by the Committee and consistent with the Plan's
purpose and applicable law, including promissory notes or a properly executed
exercise notice together with irrevocable instructions to a broker acceptable to
the Company to promptly deliver to the Company the amount of sale or loan
proceeds to pay the exercise price. As determined by the Committee, in its sole
discretion, payment in full or in part may also be made in the form of
unrestricted Stock already owned by the optionee (based on the Fair Market Value
of the Stock on the date the option is exercised, as determined by the
Committee); provided, however, that, in the case of an Incentive Stock Option,
the right to make a payment in the form of already owned shares may be
authorized only at the time the option is granted. If the terms of an option so
permit, or the Committee so provides, an optionee may select to pay all or part
of the option exercise price by having the Company withhold from the shares of
Stock that would otherwise be issued upon exercise that number of shares of
Stock having a Fair Market Value equal to the aggregate option exercise price
for the shares with respect to which such election is made. No shares of Stock
shall be issued until full payment therefor has been made. An optionee shall
generally have the rights to dividends and other rights of a stockholder with
respect to shares subject to the option when the optionee has given written
notice of exercise, has paid in full for such shares, and, if requested, has
given the representation described in paragraph (a) of Section 9.

         (e) NON-TRANSFERABILITY OF OPTIONS. No Stock Option shall be
transferable by the optionee otherwise than by will or by the laws of descent
and distribution, and all Stock Options shall be exercisable, during the
optionee's lifetime, only by the optionee.

         (f) TERMINATION BY DEATH. If an optionee's employment by the Company
and any Subsidiary or Parent Corporation terminates by reason of death, the
Stock Option may thereafter be immediately exercised, to the extent then
exercisable (or on such accelerated basis as the Committee shall determine at or
after grant), by the legal representative of the estate or by the legatee of the
optionee under the will of the optionee, for a period of two years (or such
shorter period as the Committee shall specify at grant) from the date of such
death or until the expiration of the stated term of the option, whichever period
is shorter.

         (g) TERMINATION BY REASON OF DISABILITY. If an optionee's employment by
the Company and any Subsidiary or Parent Corporation terminates by reason of
Disability, any Stock Option held by such optionee may thereafter be exercised,
to the extent it was exercisable at the time of termination due to Disability
(or on such accelerated basis as the Committee shall


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determine at or after grant), but may not be exercised after two years (or
such shorter period as the Committee shall specify at grant) from the date of
such termination of employment or the expiration of the stated term of the
option, whichever period is the shorter. In the event of termination of
employment by reason of Disability, if an Incentive Stock Option is exercised
after the expiration of the exercise periods that apply for purposes of
Section 422 of the Code, the option will thereafter be treated as a
Non-Qualified Stock Option.

         (h) TERMINATION BY REASON OF RETIREMENT. If an optionee's employment by
the Company and any Subsidiary or Parent Corporation terminates by reason of
Retirement, any Stock Option held by such optionee may thereafter be exercised
to the extent it was exercisable at the time of such Retirement, but may not be
exercised after two years (or such shorter period as Committee shall specify at
grant) from the date of such termination of employment or the expiration of the
stated term of the option, whichever period is the shorter. In the event of
termination of employment by reason of Retirement, if any Incentive Stock Option
is exercised after the expiration of the exercise periods that apply for purpose
of Section 422 of the Code, the option will thereafter be treated as a
Non-Qualified Stock Option.

         (i) OTHER TERMINATION. Unless otherwise determined by the Committee, if
an optionee's employment by the Company, any Subsidiary or Parent corporation
terminates for any reason other than death, Disability or Retirement, any Stock
Option held by such optionee may thereafter be exercised to the extent it was
exercisable at such termination for the lesser of three months or the balance of
the option's term if the optionee is involuntarily terminated without Cause by
the Company, any Subsidiary or Parent Corporation; provided, however, that if
the optionee's employment is terminated for Cause, all rights under the Stock
Option shall terminate and expire upon such termination.

         (j) ANNUAL LIMIT ON INCENTIVE STOCK OPTIONS. The aggregate Fair Market
Value (determined as of the time the option is granted) of the Common Stock with
respect to which an Incentive Stock Option under this Plan or any other plan of
the Company, any Subsidiary or Parent Corporation is exercisable for the first
time by an optionee during any calendar year shall not exceed $100,000.

         (k) NON-EMPLOYEE DIRECTOR OPTIONS. All Options granted to Non-Employee
Directors hereunder shall be designated as Non-Qualified Options and shall be
subject to the same terms and provisions as are then in effect with respect to
granting of Non-Qualified Options to officers and key employees of the Company.
No other Options shall be granted to Non-Employee Directors under the Plan or
any other Stock Plan of the Company. All provisions of this Plan not
inconsistent with the terms of this Section 5(k) shall apply to Non-Qualified
Options granted to Non-Employee Directors.


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         SECTION 6.  TRANSFER, LEAVE OF ABSENCE, ETC.

         For purposes of the Plan, the following events shall not be deemed a
termination of employment:

         (a) a transfer of an employee from the Company to a Parent Corporation
or Subsidiary, or from a Parent Corporation or Subsidiary to the Company, or
from one Subsidiary to another;

         (b) a leave of absence, approved in writing by the Committee, for
military service or sickness, or for any other purpose approved by the Company
if the period of such leave does not exceed ninety (90) days (or such longer
period as the Committee may approve, in its sole discretion); and

         (c) a leave of absence in excess of ninety (90) days, approved in
writing by the Committee, but only if the employee's right to re-employment is
guaranteed either by a statute or by contract, and provided that, in the case of
any leave of absence, the employee returns to work within 30 days after the end
of such leave.

         SECTION 7.  AMENDMENTS AND TERMINATION.

         The Board may amend, alter, or discontinue the Plan, but no amendment,
alteration, or discontinuation shall be made (i) which would impair the rights
of an optionee under a Stock Option award theretofore granted, without the
optionee's consent, or (ii) which without the approval of the stockholders of
the Company would cause the Plan to no longer comply with rules promulgated by
the Securities and Exchange Commission under authority granted in Section 16 of
the Securities Exchange Act of 1934, as amended, Section 422 of the Code or any
other regulatory requirements.

         The Committee may amend the terms of any award or option theretofore
granted, prospectively or retroactively, but, subject to Section 3 above, no
such amendment shall impair the rights of any holder without his consent. The
Committee may also substitute new Stock Options for previously granted options,
including previously granted options having higher option prices.

         SECTION 8.  UNFUNDED STATUS OF PLAN.

         The Plan is intended to constitute an "unfunded" plan for incentive and
deferred compensation. With respect to any payments not yet made to a
participant or optionee by the Company, nothing contained herein shall give any
such participant or optionee any rights that are greater than those of a general
creditor of the Company. In its sole discretion, the Committee may authorize the
creation of trusts or other arrangements to meet the obligations created under
the Plan to deliver Stock or payments in lieu of or with respect to awards
hereunder, provided,


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however, that the existence of such trusts or other arrangements is
consistent with the unfunded status of the Plan.

         SECTION 9.  GENERAL PROVISIONS.

         (a) The Committee may require each person purchasing shares pursuant to
a Stock Option under the Plan to represent to and agree with the Company in
writing that the optionee is acquiring the shares without a view to distribution
thereof. The certificates for such shares may include any legend which the
Committee deems appropriate to reflect any restrictions on transfer. All
certificates for shares of Stock delivered under the Plan pursuant to any Option
shall be subject to such stock transfer orders and other restrictions as the
Committee may deem advisable under the rules, regulations, and other
requirements of the Securities and Exchange Commission, any stock exchange upon
which the Stock is then listed, and any applicable Federal or state securities
laws, and the Committee may cause a legend or legends to be put on any such
certificates to make appropriate reference to such restrictions.

         (b) Nothing contained in this Plan shall prevent the Board of Directors
from adopting other or additional compensation arrangements, subject to
stockholder approval if such approval is required; and such arrangements may be
either generally applicable or applicable only in specific cases. The adoption
of the Plan shall not confer upon any employee of the Company or any Subsidiary
any right to continued employment with the Company or a Subsidiary, as the case
may be, nor shall it interfere in any way with the right of the Company or a
subsidiary to terminate the employment of any of its employees at any time.

         (c) Each participant shall, no later than the date as of which any part
of the value of an award first becomes includible as compensation in the gross
income of the participant for Federal income tax purposes, pay to the Company,
or make arrangements satisfactory to the Committee regarding payment of, any
Federal, state, or local taxes of any kind required by law to be withheld with
respect to the award. The obligations of the Company under the Plan shall be
conditional on such payment or arrangements and the Company and Subsidiaries
shall, to the extent permitted by law, have the right to deduct any such taxes
from any payment of any kind otherwise due to the participant. With respect to
any award under the Plan, if the written terms of such award so permit, a
participant may elect by written notice to the Company to satisfy part or all of
the withholding tax requirements associated with the award by (i) authorizing
the Company to retain from the number of shares of Stock that would otherwise be
deliverable to the participant, or (ii) delivering to the Company from shares of
Stock already owned by the participant, that number of shares having an
aggregate Fair Market Value equal to part or all of the tax payable by the
participant under this Section 9(c). Any such election shall be in accordance
with, and subject to, applicable tax and securities laws, regulations and
rulings.

         (d) At the time of grant, the Committee may provide in connection with
any grant made under this Plan that the shares of Stock received as a result of
such grant shall be subject to a repurchase right in favor of the Company,
pursuant to which the participant shall be required to


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offer to the Company upon termination of employment for any reason any shares
that the then Fair Market Value of the Stock or, in the case of a termination
for Cause, an amount equal to the cash consideration paid for the Stock,
subject to such other terms and conditions as the Committee may specify at
the time of grant. The Committee may, at the time of the grant of an award
under the Plan, provide the Company with the right to repurchase shares of
Stock acquired pursuant to the Plan by any participant who, at any time
within two years after termination of employment with the Company directly or
indirectly competes with, or is employed by a competitor of, the Company.

         SECTION 10.  EFFECTIVE DATE OF PLAN.

         The Plan shall be effective on June 29, 1993, subject to approval by a
vote of the holders of a majority of the Stock present and entitled to vote at
the next Annual or Special Meeting of the Company's stockholders and shall
expire (unless terminated earlier) as of June 26, 2008. Awards may be granted
under the Plan prior to stockholder approval, provided such awards are made
subject to stockholder approval.


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