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                           CALYPTE BIOMEDICAL CORPORATION

                               1991 STOCK OPTION PLAN
                          AMENDED AS OF NOVEMBER 18, 1999


     1.   PURPOSES OF THE PLAN.  The purposes of this Stock Option Plan are to
attract and retain the best available personnel for positions of substantial
responsibility, to provide additional incentive to the Employees and Consultants
of the Company and to promote the success of the Company's business.

     Options granted hereunder may be either Incentive Stock Options or
Nonstatutory Stock Options, at the discretion of the Board and as reflected in
the terms of the written option agreement.

     2.   DEFINITIONS.  As used herein, the following definitions shall apply:

          (a)  "Board" shall mean the Committee, if one has been appointed, or
the Board of Directors of the Company, if no Committee is appointed.

          (b)  "Code" shall mean the Internal Revenue Code of 1986, as amended.

          (c)  "Committee" shall mean the Committee appointed by the Board of
Directors in accordance with paragraph (a) of Section 4 of the Plan, if one is
appointed.

          (d)  "Common Stock" shall mean the Common Stock of the Company.

          (e)  "Company" shall mean Calypte Biomedical Corporation, a California
corporation.

          (f)  "Consultant" shall mean any person who is engaged by the Company
or any Parent or Subsidiary to render consulting services and is compensated for
such consulting services, and any director of the Company who is not an Employee
whether compensated for such services or not; provided that if and in the event
the Company registers any class of any equity security pursuant to Section 12 of
the Securities Exchange Act of 1934, as amended (the "Exchange Act"), the term
Consultant shall thereafter not include directors who are not compensated for
their services or are paid only a director's fee by the Company.

          (g)  "Continuous Status as an Employee or Consultant" shall mean the
absence of any interruption or termination of service as an Employee or
Consultant.  Continuous Status as an Employee or Consultant shall not be
considered interrupted in the case of sick leave, military leave, or any other
leave of absence approved by the Board; provided that such leave is for a period
of not more than 90 days or reemployment upon the expiration of such leave is
guaranteed by contract or statute.

          (h)  "Employee" shall mean any person, including officers and
directors, employed by the Company or any Parent or Subsidiary of the Company.
The payment of a director's fee by the Company shall not be sufficient to
constitute "employment" by the company.

          (i)  "Incentive Stock option" shall mean an Option intended to qualify
as an incentive stock option within the meaning of Section 422 of the Code.

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          (j)  "Nonstatutory Stock Option" shall mean an Option not intended to
qualify as an Incentive Stock Option.

          (k)  "Option" shall mean a stock option granted pursuant to the Plan.

          (l)  "Optioned Stock" shall mean the Common Stock subject to an
Option.

          (m)  "Optionee" shall mean an Employee or Consultant who receives an
Option.

          (n)  "Parent" shall mean a "parent corporation", whether now or
hereafter existing, as defined in Section 424(e) of the Code.

          (o)  "Plan" shall mean this 1991 Stock Option Plan.

          (p)  "Share" shall mean a share of the Common Stock, as adjusted in
accordance with Section 11 of the Plan.

          (q)  "Subsidiary" shall mean a "subsidiary corporation", whether now
or hereafter existing, as defined in Section 424(f) of the Code.

     3.   STOCK SUBJECT TO THE PLAN.  Subject to the provisions of Section 11 of
the Plan, the maximum aggregate number of shares which may be optioned and sold
under the Plan is 4,240,992 shares of Common Stock.  The Shares may be
authorized, but unissued, or reacquired Common Stock. If an Option should expire
or become unexercisable for any reason without having been exercised in full,
the unpurchased Shares which were subject thereto shall, unless the Plan shall
have been terminated, become available for future grant under the Plan.  Shares
issued under the Plan and later repurchased by the Company shall also become
available for future grant or sale under the Plan.

     4.   ADMINISTRATION OF THE PLAN.

          (a)  Procedure.  The Plan shall be administered by the Board of
Directors of the Company.

               (i)   Subject to subparagraph (ii), the Board of Directors may
appoint a committee consisting of not less than two members of the Board of
Directors to administer the Plan on behalf of the Board of Directors, subject to
such terms and conditions as the Board of Directors may prescribe. Once
appointed, the Committee shall continue to serve until otherwise directed by the
Board of Directors.  Members of the Board who are either eligible for Options or
have been granted Options may vote on any matters affecting the administration
of the Plan or the grant of any Options pursuant to the Plan, except that no
such member shall act upon the granting of an option to himself, but any such
member may be counted in determining the existence of a quorum at any meeting of
the Board during which action is taken with respect to the granting of Options
to him.

               (ii)  Notwithstanding the foregoing subparagraph (i), if the
Company registers any class of any equity security pursuant to Section 12 of the
Exchange Act, from the effective date of such registration until six months
after the termination of such registration, any grants of Options to officers or
directors shall only be made by the Board of Directors; provided, however, that
if a majority of the Board of Directors is eligible to participate in this Plan
or any other stock option or other stock plan of the Company or any of its
affiliates, or has been eligible

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at any time during the prior one-year period (or, if shorter, the period
following the initial registration of the Company's equity securities under
Section 12 of the Exchange Act), any grants of Options to directors must be
made by, or only in accordance with the recommendation of, a Committee
consisting of three or more persons, who may but need not be directors or
employees of the Company, appointed by the Board of Directors and having full
authority to act in the matter, none of whom is eligible to participate in
this Plan or any other stock option or other stock plan of the Company or any
of its affiliates, or has been eligible at any time during the prior one-year
period (or, if shorter, the period following the initial registration of the
Company's equity securities under Section 12 of the Exchange Act).  Any
Committee administering the Plan with respect to grants to officers who are
not also directors shall conform to the requirements of the preceding
sentence. Once appointed, the Committee shall continue to serve until
otherwise directed by the Board of Directors.  (iii)   Subject to the
foregoing subparagraphs (i) and (ii), from time to time the Board of
Directors may increase the size of the Committee and appoint additional
members thereof, remove members (with or without cause) and appoint new
members in substitution therefor, fill vacancies however caused, or remove
all members of the Committee and thereafter directly administer the Plan.

          (b)  Powers of the Board.  Subject to the provisions of the Plan,
the Board shall have the authority, in its discretion: (i) to grant Incentive
Stock Options or Nonstatutory Stock Options; (ii) to determine, upon review
of relevant information and in accordance with Section 8(b) of the Plan, the
fair market value of the Common Stock; (iii) to determine the exercise price
per share of Options to be granted, which exercise price shall be determined
in accordance with Section 8(a) of the Plan; (iv) to determine the Employees
or Consultants to whom, and the time or times at which, Options shall be
granted and the number of shares to be represented by each Option; (v) to
interpret the Plan; (vi) to prescribe, amend and rescind rules and
regulations relating to the Plan; (vii) to determine the terms and provisions
of each Option granted (which need not be identical) and, with the consent of
the holder thereof, modify or amend each Option; (viii) to defer (with the
consent of the Optionee) the exercise date of any Option, consistent with the
provisions of Section 5 of the Plan; (ix) to authorize any person to execute
on behalf of the Company any instrument required to effectuate the grant of
an Option previously granted by the Board; and (x) to make all other
determinations deemed necessary or advisable for the administration of the
Plan.

          (c)  Effect of Board's Decision.  All decisions, determinations and
interpretations of the Board shall be final and binding and all Optionees and
any other holders of any Options granted under the Plan.

     5.   ELIGIBILITY.

          (a)  Nonstatutory Stock Options may be granted only to Employees
and Consultants.  Incentive Stock Options may be granted only to Employees.
An Employee or Consultant who has been granted an Option may, if he is
otherwise eligible, be granted an additional Option or Options.

          (b)  Each Option shall be designated in the written option
agreement as either an Incentive Stock Option or a Nonstatutory Stock Option.
However, notwithstanding such designations, to the extent that the aggregate
fair market value of the Shares with respect to which Options designated as
Incentive Stock Options are exercisable for the first time by any Optionee
during any calendar year (under all plans of the Company, its Parent or
Subsidiaries) exceeds $100,000, such Options shall be treated as Nonstatutory
Stock Options.

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          (c)  For purposes of Section 5(b), Options shall be taken into
account in the order in which they were granted, and the fair market value of
the Shares shall be determined as of the time the Option with respect to such
Shares is granted.

          (d)  The Plan shall not confer upon any Optionee any right with
respect to continuation of employment or consulting relationship with the
Company, nor shall it interfere in any way with his right or the Company's
right to terminate his employment or consulting relationship at any time,
with or without cause.

     6.   TERM OF PLAN.  The Plan shall become effective upon the earlier to
occur of its adoption by the Board of Directors or its approval by the
shareholders of the Company as described in Section 17 of the Plan. It shall
continue in effect for a term of ten (10) years unless sooner terminated
under Section 13 of the Plan.

     7.   TERM OF OPTION.  The term of each option shall be ten (10) years
from the date of grant thereof or such shorter term as may be provided in the
Option Agreement.  However, in the case of an Option granted to an optionee
who, at the time the Option is granted, owns stock representing more than ten
percent (10%) of the voting power of all classes of stock of the Company or
any Parent or Subsidiary, if the Option is an Incentive Stock Option, the
term of the Option shall be five (5) years from the date of grant thereof or
such shorter term as may be provided in the Incentive Stock Option Agreement.

     8.   EXERCISE PRICE AND CONSIDERATION.

          (a)  The per Share exercise price for the Shares to be issued
pursuant to exercise of an Option shall be such price as is determined by the
Board, but shall be subject to the following:

               (i)   In the case of an Incentive Stock Option

                     (A) granted to an Employee who, at the time of the grant
of such Incentive Stock Option, owns stock representing more than ten percent
(10%) of the voting power of all classes of stock of the Company or any
Parent or Subsidiary, the per Share exercise price shall be no less than 110%
of the fair market value per Share on the date of grant;

                     (B) granted to any other Employee, the per Share
exercise price shall be no less than 100% of the fair market value per Share
on the date of grant.

               (ii)  In the case of a Nonstatutory Stock Option

                     (A) granted to a person who, at the time of the grant of
such Option, owns stock representing more than ten percent (10%) of the
voting power of all classes of stock of the Company or any Parent or
Subsidiary, the per Share exercise price shall be no less than 110% of the
fair market value per Share on the date of the grant;

                     (B) granted to any other person, the per Share exercise
price shall be no less than 85% of the fair market value per Share on the
date of grant.

For purposes of this Section 8(a), in the event that an Option is amended to
reduce the exercise price, the date of grant of such Option shall thereafter
be considered to be the date of such amendment.

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          (b)  The fair market value shall be determined by the Board in its
discretion; provided, however, that where there is a public market for the
Common Stock, the fair market value per Share shall be the mean of the bid
and asked prices (or the closing price per share if the Common Stock is
listed on the National Association of Securities Dealers Automated Quotation
("NASDAQ") National Market System) of the Common Stock for the date of grant,
as reported in the Wall Street Journal (or, if not so reported, as otherwise
reported by the NASDAQ System) or, in the event the Common Stock is listed on
a stock exchange, the fair market value per Share shall be the closing price
on such exchange on the date of grant of the Option, as reported in the Wall
Street Journal.

          (c)  The consideration to be paid for the Shares to be issued upon
exercise of an Option, including the method of payment, shall be determined
by the Board and may consist entirely of cash, check, promissory note, other
Shares of Common Stock which (i) either have been owned by the Optionee for
more than six (6) months on the date of surrender or were not acquired,
directly or indirectly, from the Company, and (ii) have a fair market value
on the date of surrender equal to the aggregate exercise price of the Shares
as to which said Option shall be exercised, or any combination of such
methods of payment, or such other consideration and method of payment for the
issuance of Shares to the extent permitted under Sections 408 and 409 of the
California General Corporation Law.  In making its determination as to the
type of consideration to accept, the Board shall consider if acceptance of
such consideration may be reasonably expected to benefit the Company (Section
315(b) of the California General Corporation Law).

     9.   EXERCISE OF OPTION.

          (a)  Procedure for Exercise; Rights as a Shareholder.  Any Option
granted hereunder shall be exercisable at such times and under such
conditions as determined by the Board, including performance criteria with
respect to the Company and/or the Optionee, and as shall be permissible under
the terms of the Plan. An Option may not be exercised for a fraction of a
Share. An Option shall be deemed to be exercised when written notice of such
exercise has been given to the Company in accordance with the terms of the
Option by the person entitled to exercise the Option and full payment for the
Shares with respect to which the Option is exercised has been received by the
Company.  Full payment may, as authorized by the Board, consist of any
consideration and method of payment allowable under Section 8(c) of the Plan.
Until the issuance (as evidenced by the appropriate entry on the books of the
Company or of a duly authorized transfer agent of the Company) of the stock
certificate evidencing such Shares, no right to vote or receive dividends or
any other rights as a shareholder shall exist with respect to the Optioned
Stock, notwithstanding the exercise of the Option.  The Company shall issue
(or cause to be issued) such stock certificate promptly upon exercise of the
Option.  In the event that the exercise of an Option is treated in part as
the exercise of an Incentive Stock Option and in part as the exercise of a
Nonstatutory Stock Option pursuant to Section 5(b), the Company shall issue a
separate stock certificate evidencing the Shares treated as acquired upon
exercise of an Incentive Stock Option and a separate stock certificate
evidencing the Shares treated as acquired upon exercise of a Nonstatutory
Stock Option, and shall identify each such certificate accordingly in its
stock transfer records.  No adjustment will be made for a dividend or other
right for which the record date is prior to the date the stock certificate is
issued, except as provided in Section 11 of the Plan. Exercise of an Option
in any manner shall resul in a  decrease in the number of Shares which
thereafter may be available, both for  purposes of the Plan and for sale
under the Option, by the number of Shares as  to which the Option is
exercised.

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          (b)  Termination of Status as an Employee or Consultant. In the
event of termination of an Optionee's Continuous Status as an Employee or
Consultant (as the case may be), such Optionee may, but only within three (3)
months (or such shorter period of time as is determined by the Board and
specified in the Option Agreement) after the date of such termination (but in
no event later than the date of expiration of the term of such Option as set
forth in the Option Agreement), exercise his Option to the extent that he was
entitled to exercise it at the date of such termination.  To the extent that
he was not entitled to exercise the Option at the date of such termination,
or if he does not exercise such Option (which he was entitled to exercise)
within the time specified herein, the Option shall terminate.

          (c)  Disability of Optionee.  Notwithstanding the provisions of
Section 9 (b) above, in the event of termination of an Optionee's Continuous
Status as an Employee or Consultant as a result of his total and permanent
disability (as defined in Section 22(e)(3) of the Code), he may, but only
within six (6) months from the date of such termination (but in no event
later than the date of expiration of the term of such Option as set forth in
the Option Agreement), exercise his Option to the extent he was entitled to
exercise it at the date of such termination.  To the extent that he was not
entitled to exercise the Option at the date of termination, or if he does not
exercise such Option (which he was entitled to exercise) within the time
specified herein, the Option shall terminate.

          (d)  Death of Optionee.  Notwithstanding the provisions of Section
9(b) above, in the event of the death of an Optionee:

               (i)   during the term of the Option who is at the time of his
death an Employee or Consultant of the Company and who shall have been in
Continuous Status as an Employee or Consultant since the date of grant of the
Option, the Option may be exercised, at any time within six (6) months
following the date of termination (but in no event later than the date of
expiration of the term of such Option as set forth in the Option Agreement),
by the Optionee's estate or by a person who acquired the right to exercise
the Option by bequest or inheritance, but only to the extent that the right
to exercise had accrued as of the date of death of the Optionee; or

               (ii)  within thirty (30) days after the termination of
Continuous Status as an Employee or Consultant, the Option may be exercised,
at any time within six (6) months following the date of death (but in no
event later than the date of expiration of the term of such Option as set
forth in the Option Agreement), by the Optionee's estate or by a person who
acquired the right to exercise the Option by bequest or inheritance, but only
to the extent of the right to exercise that had accrued at the date of
termination.

     10.  NON-TRANSFERABILITY OF OPTIONS.  The Option may not be sold,
pledged, assigned, hypothecated, transferred, or disposed of in any manner
other than by will or by the laws of descent or distribution and may be
exercised, during the lifetime of the Optionee, only by the Optionee.

     11.  ADJUSTMENTS UPON CHANGES IN CAPITALIZATION OR MERGER.  Subject to
any required action by the shareholders of the Company, the number of shares
of Common Stock covered by each outstanding Option, and the number of shares
of Common Stock which have been authorized for issuance under the Plan but as
to which no Options have yet been granted or which have been returned to the
Plan upon cancellation or expiration of an Option, as well as the price per
share of Common Stock covered by each such outstanding Option, shall be
proportionately adjusted for any increase or decrease in the number of issued
shares of Common

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Stock resulting from a stock split, reverse stock split, stock dividend,
combination or reclassification of the Common Stock, or any other increase or
decrease in the number of issued shares of Common Stock effected without
receipt of consideration by the Company; provided, however, that conversion
of any convertible securities of the Company shall not be deemed to have been
"effected without receipt of consideration." Such adjustment shall be made by
the Board, whose determination in that respect shall be final, binding and
conclusive. Except as expressly provided herein, no issuance by the Company
of shares of stock of any class, or securities convertible into shares of
stock of any class, shall affect, and no adjustment by reason thereof shall
be made with respect to, the number or price of shares of Common Stock
subject to an Option. In the event of the proposed dissolution or liquidation
of the Company, the Board shall notify the Optionee at least fifteen (15)
days prior to such proposed action. To the extent it has not been previously
exercised, the Option will terminate immediately prior to the consummation of
such proposed action.

     12.  TIME OF GRANTING OPTIONS.  The date of grant of an Option shall
unless otherwise fixed by the Board, be the date on which the Board makes the
determination granting such Option.  Notice of the determination shall be
given to each Employee or Consultant to whom an Option is so granted within a
reasonable time after the date of such grant.

     13.  AMENDMENT AND TERMINATION OF THE PLAN.

          (a)  Amendment and Termination.  The Board may amend or terminate
the Plan from time to time in such respects as the Board may deem advisable;
provided that, the following revisions or amendments shall require approval
of the shareholders of the Company in the manner described in Section 17 of
the Plan:

               (i)   any increase in the number of Shares subject to the
Plan, other than in connection with an adjustment under Section 11 of the
Plan;

               (ii)  any change in the designation of the class of persons
eligible to be granted Options; or

               (iii) if the Company has a class of equity securities
registered under Section 12 of the Exchange Act at the time of such revision
or amendment, any material increase in the benefits accruing to participants
under the Plan.

          (b)  Shareholder Approval.  If any amendment requiring shareholder
approval under Section 13(a) of the Plan is made subsequent to the first
registration of any class of equity securities by the Company under Section
12 of the Exchange Act, such shareholder approval shall be solicited as
described in Section 17 of the Plan.

          (c)  Effect of Amendment or Termination.  Any such amendment or
termination of the Plan shall not affect Options already granted and such
Options shall remain in full force and effect as if this Plan had not been
amended or terminated, unless mutually agreed otherwise between the Optionee
and the Board, which agreement must be in writing and signed by the Optionee
and the Company.

     14.  CONDITIONS UPON ISSUANCE OF SHARES.  Shares shall not be issued
pursuant to the exercise of an Option unless the exercise of such Option and
the issuance and delivery of such Shares pursuant thereto shall comply with
all relevant provisions of law, including, without limitation, the Securities
Act of 1933, as amended, the Exchange Act, the rules and regulations

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promulgated thereunder, and the requirements of any stock exchange upon which
the Shares may then be listed, and shall be further subject to the approval
of counsel for the Company with respect to such compliance. As a condition to
the exercise of an Option, the Company may require the person exercising such
Option to represent and warrant at the time of any such exercise that the
Shares are being purchased only for investment and without any present
intention to sell or distribute such Shares if, in the opinion of counsel for
the Company, such a representation is required by any of the aforementioned
relevant provisions of law.

     15.  RESERVATION OF SHARES.  The Company, during the term of this Plan,
will at all times reserve and keep available such number of Shares as shall
be sufficient to satisfy the requirements of the Plan. The inability of the
Company to obtain authority from any regulatory body having jurisdiction,
which authority is deemed by the Company's counsel to be necessary to the
lawful issuance and sale of any Shares hereunder, shall relieve the Company
of any liability in respect of the failure to issue or sell such Shares as to
which such requisite authority shall not have been obtained.

     16.  OPTION AGREEMENT. Options shall be evidenced by written option
agreements in such form as the Board shall approve.

     17.  SHAREHOLDER APPROVAL.

          (a)  continuance of the Plan shall be subject to approval by the
shareholders of the Company within twelve (12) months before or after the
date the Plan is adopted.

          (b)  If and in the event that the Company registers any class of
equity securities pursuant to Section 12 of the Exchange Act, any required
approval of the shareholders of the Company obtained after such registration
shall be solicited substantially in accordance with Section 14(a) of the
Exchange Act and the rules and regulations promulgated thereunder.

          (c)  if any required approval by the shareholders of the Plan
itself or of any amendment thereto is solicited at any time otherwise than in
the manner described in Section 17(b) hereof, then the Company shall, at or
prior to the first annual meeting of shareholders held subsequent to the
later of (1) the first registration of any class of equity securities of the
Company under Section 12 of the Exchange Act or (2) the granting of an option
hereunder to an officer or director after such registration, do the following:

               (i)   furnish in writing to the holders entitled to vote for
the Plan substantially the same information which would be required (if
proxies to be voted with respect to approval or disapproval of the Plan or
amendment were then being solicited) by the rules and regulations in effect
under Section 14(a) of the Exchange Act at the time such information is
furnished; and

               (ii)  file with, or mail for filing to, the Securities and
Exchange Commission four copies of the written information referred to in
subsection (i) hereof not later than the date on which such information is
first sent or given to shareholders.

     18.  INFORMATION TO OPTIONEES. The Company shall provide to its security
holders financial statements at least annually.  The Company shall not be
required to provide such information to key employees whose duties in
connection with the Company assure their access to equivalent information.


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