<PAGE>

                                                                     EXHIBIT 4.3

                         CALYPTE BIOMEDICAL CORPORATION
                        1995 EMPLOYEE STOCK PURCHASE PLAN
                            (AS AMENDED MAY 20, 2003)

         The following constitute the provisions of the Employee Stock Purchase
Plan of Calypte Biomedical Corporation.

         1. Purpose. The purpose of the Plan is to provide employees of the
Company and its Designated Subsidiaries with an opportunity to purchase Common
Stock of the Company through accumulated payroll deductions. It is the intention
of the Company to have the Plan qualify as an "Employee Stock Purchase Plan"
under Section 423 of the Internal Revenue Code of 1986, as amended. The
provisions of the Plan, accordingly, shall be construed so as to extend and
limit participation in a manner consistent with the requirements of that section
of the Code.

         2.      Definitions.
                 (a) "Board" shall mean the Board of Directors of the Company.

                 (b) "Code" shall mean the Internal Revenue Code of 1986, as
amended.
                 (c) "Common Stock" shall mean the Common Stock of the Company,
$0.03 par value.
                 (d) "Company" shall mean Calypte Biomedical Corporation and any
Designated Subsidiary of the Company. (e) "Compensation" shall mean all
compensation reportable on Form W-2, including without limitation base straight
time gross earnings, sales commissions, payments for overtime, shift premiums,
incentive compensation, incentive payments, bonuses and other compensation.
                 (f) "Designated Subsidiaries" shall mean the Subsidiaries which
have been designated by the Board from time to time in its sole discretion as
eligible to participate in the Plan.
                 (g) "Employee" shall mean any individual who is an Employee of
the Company for tax purposes whose customary employment with the Company is at
least twenty (20) hours per week and more than five (5) months in any calendar
year. For purposes of the Plan, the employment relationship shall be treated as
continuing intact while the individual is on sick leave or other leave of
absence approved by the Company. Where the period of leave exceeds 90 days and
the individual's right to reemployment is not guaranteed either by statute or by
contract, the employment relationship will be deemed to have terminated on the
91st day of such leave.
                 (h) "Enrollment Date" shall mean the first day of each Offering
Period.
                 (i) "Exercise Date" shall mean the last day of each
Offering Period.
                 (j) "Fair Market Value" shall mean, as of any date, the value
of Common Stock determined as follows: If the Common Stock is listed on any
established stock exchange or a national market system, including without
limitation the National Market System of the National Association of Securities
Dealers, Inc. Automated Quotation ("NASDAQ") System, its Fair Market Value shall
be the closing sale price for the Common Stock (or the mean of the closing bid
and asked prices, if no sales were reported), as quoted on such exchange (or the
exchange with the greatest volume of trading in Common Stock) or system on the
date of such determination, as reported in The Wall Street Journal or such other
source as the Board deems reliable, or;
                          (2) If the Common Stock is quoted on the NASDAQ system
(but not on the National Market System thereof) or is regularly quoted by a
recognized securities dealer but selling prices are not reported, its
Fair Market Value shall be the mean of the closing bid and asked prices for
the Common Stock on the date of such determination, as reported
in The Wall Street Journal or such other source as the Board deems reliable, or;
                          (3) In the absence of an established market for the
Common Stock, the Fair Market Value thereof shall be determined in good
faith by the Board.
                          (4) For purposes of the Enrollment Date under the
first Offering Period under the Plan, the Fair Market Value shall be the
initial price to the public as set forth in the final Prospectus included
within the Registration Statement in Form S-1 filed with the Securities and
Exchange Commission for the initial public offering of the Company's
Common Stock.


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                 (k) "Offering Period" shall mean a period of approximately six
(6) months, commencing on the first Trading Day on or after May 1 and
terminating on the last Trading Day in the period ending the following October
31, or commencing on the first Trading Day on or after November 1 and
terminating on the last Trading Day in the period ending the following April 30,
during which an option granted pursuant to the Plan may be exercised. The first
Offering Period shall begin on the effective date of the Company's initial
public offering of its Common Stock that is registered with the Securities and
Exchange Commission and shall end on the last Trading Day on or before April 30,
1996. The duration of Offering Periods may be changed pursuant to Section 4 of
this Plan. The initial Offering Period shall be determined by the Board of
Directors.
                 (l) "Officer" means a person who is an officer of the Company
within the meaning of Section 16 of the Exchange Act and the rules and
regulations promulgated thereunder.
                 (m) "Plan" shall mean this Employee Stock Purchase Plan.
                 (n) "Purchase Price" shall mean an amount equal to 85% of the
Fair Market Value of a share of Common Stock on the Enrollment Date or on the
Exercise Date, whichever is lower.
                 (o) "Reserves" shall mean the number of shares of Common Stock
covered by each option under the Plan which have not yet been exercised and the
number of shares of Common Stock which have been authorized for issuance under
the Plan but not yet placed under option.
                 (p) "Subsidiary" shall mean a corporation, domestic or foreign,
of which not less than 50% of the voting shares are held by the Company or a
Subsidiary, whether or not such corporation now exists or is hereafter organized
or acquired by the Company or a Subsidiary.
                 (q) "Trading Day" shall mean a day on which national stock
exchanges and the National Association of Securities Dealers Automated Quotation
(NASDAQ) System are open for trading.

         3. Eligibility.
                 (a) Any Employee (as defined in Section 2(g)), who shall be
employed by the Company on a given Enrollment Date shall be eligible to
participate in the Plan.
                 (b) Any provisions of the Plan to the contrary notwithstanding,
no Employee shall be granted an option under the Plan (i) to the extent,
immediately after the grant, such Employee (or any other person whose stock
would be attributed to such Employee pursuant to Section 424(d) of the Code)
would own capital stock of the Company and/or hold outstanding options to
purchase such stock possessing five percent (5%) or more of the total combined
voting power or value of all classes of the capital stock of the Company or of
any Subsidiary, or (ii) to the extent his or her rights to purchase stock under
all employee stock purchase plans of the Company and its subsidiaries to accrue
at a rate which exceeds Twenty-Five Thousand Dollars ($25,000) worth of stock
(determined at the fair market value of the shares at the time such option is
granted) for each calendar year in which such option is outstanding at any time.

         4. Offering Periods. The Plan shall be implemented by consecutive
Offering Periods with a new Offering Period commencing on the first Trading Day
on or after May 1 and November 1 each year, or on such other date as the Board
shall determine, and continuing thereafter until terminated in accordance with
Section 19 hereof. The first Offering Period shall begin on the effective date
of the Company's initial public offering of its Common Stock that is registered
with the Securities and Exchange Commission. The Board shall have the power to
change the duration of Offering Periods (including the commencement dates
thereof) with respect to future offerings without shareholder approval if such
change is announced at least fifteen (15) days prior to the scheduled beginning
of the first Offering Period to be affected thereafter.

         5. Participation.
                 (a) An eligible Employee may become a participant in the Plan
by completing a subscription agreement authorizing payroll deductions in the
form of Exhibit A to this Plan and filing it with the Company's payroll office
prior to the applicable Enrollment Date. An eligible Officer may become a
participant in the Plan by completing a subscription agreement authorizing
payroll deductions and an irrevocable election in the form of Exhibit B to this
Plan and filing it with the Company's payroll office prior to the applicable
Enrollment Date.
                 (b) Payroll deductions for a participant shall commence on the
first payroll following the Enrollment Date and shall end on the last payroll in
the Offering Period to which such authorization is applicable, unless sooner
terminated by the participant as provided in Section 10 hereof.

         6. Payroll Deductions.


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                 (a) At the time a participant files his or her subscription
agreement, he or she shall elect to have payroll deductions made on each pay day
during the Offering Period in an amount not exceeding ten percent (10%) of the
Compensation which he or she receives on each pay day during the Offering
Period.
                 (b) All payroll deductions made for a participant shall be
credited to his or her account under the Plan and will be withheld in whole
percentages only. A participant may not make any additional payments into such
account.
                 (c) A participant other than Officers may discontinue his or
her participation in the Plan as provided in Section 10 hereof, or may increase
or decrease the rate of his or her payroll deductions during the Offering Period
by completing or filing with the Company a new subscription agreement
authorizing a change in payroll deduction rate. The Board may, in its
discretion, limit the number of participation rate changes during any Offering
Period. The change in rate shall be effective with the first full payroll period
following five (5) business days after the Company's receipt of the new
subscription agreement unless the Company elects to process a given change in
participation more quickly. A participant's subscription agreement shall remain
in effect for successive Offering Periods unless terminated as provided in
Section 10 hereof.
                 (d) Notwithstanding the foregoing, to the extent necessary to
comply with Section 423(b)(8) of the Code and Section 3(b) hereof, a
participant's payroll deductions may be decreased to 0% at such time during any
Offering Period which is scheduled to end during the current calendar year (the
"Current Offering Period") that the aggregate of all payroll deductions which
were previously used to purchase stock under the Plan in a prior Offering Period
which ended during that calendar year plus all payroll deductions accumulated
with respect to the Current Offering Period equal $21,250. Payroll deductions
shall recommence at the rate provided in such participant's subscription
agreement at the beginning of the first Offering Period which is scheduled to
end in the following calendar year, unless terminated by the participant as
provided in Section 10 hereof.
                 (e) At the time the option is exercised, in whole or in part,
or at the time some or all of the Company's Common Stock issued under the Plan
is disposed of, the participant must make adequate provision for the Company's
federal, state, or other tax withholding obligations, if any, which arise upon
the exercise of the option or the disposition of the Common Stock. At any time,
the Company may, but will not be obligated to, withhold from the participant's
compensation the amount necessary for the Company to meet applicable withholding
obligations, including any withholding required to make available to the Company
any tax deductions or benefits attributable to sale or early disposition of
Common Stock by the Employee.

         7. Grant of Option. On the Enrollment Date of each Offering Period,
each eligible Employee participating in such Offering Period shall be granted an
option to purchase on the Exercise Date of such Offering Period (at the
applicable Purchase Price) up to a number of shares of the Company's Common
Stock determined by dividing such Employee's payroll deductions accumulated
prior to such Exercise Date and retained in the Participant's account as of the
Exercise Date by the applicable Purchase Price; provided that in no event shall
an Employee be permitted to purchase during each Offering Period more than a
number of Shares determined by dividing $12,500 by the Fair Market Value of a
share of the Company's Common Stock on the Enrollment Date, and provided further
that such purchase shall be subject to the limitations set forth in Sections
3(b) and 12 hereof Exercise of the option shall occur as provided in Section 8
hereof, unless the participant has withdrawn pursuant to Section 10 hereof, and
shall expire on the last day of the Offering Period.

         8. Exercise of Option. Unless a participant withdraws from the Plan as
provided in Section 10 hereof, his or her option for the purchase of shares will
be exercised automatically on the Exercise Date, and the maximum number of full
shares subject to option shall be purchased for such participant at the
applicable Purchase Price with the accumulated payroll deductions in his or her
account. No fractional shares will be purchased; any payroll deductions
accumulated in a participant's account which are not sufficient to purchase a
full share shall be retained in the participant's account for the subsequent
Offering Period, subject to earlier withdrawal by the participant as provided in
Section 10 hereof. Any other monies left over in a participant's account after
the Exercise Date shall be returned to the participant. During a participant's
lifetime, a participant's option to purchase shares hereunder is exercisable
only by him or her.

         9. Delivery. As promptly as practicable after each Exercise Date on
which a purchase of shares occurs, the Company shall arrange the delivery to
each participant who requests in writing, as reasonable and appropriate, of a
certificate representing the shares purchased upon exercise of his or her
option.


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        10. Withdrawal; Termination of Employment.
                 (a) A participant may withdraw all but not less than all the
payroll deductions credited to his or her account and not yet used to exercise
his or her option under the Plan at any time by giving written notice to the
Company in the form of Exhibit C to this Plan. All of the participant's payroll
deductions credited to his or her account will be paid to such participant
promptly after receipt of notice of withdrawal and such participant's option for
the Offering Period will be automatically terminated, and no further payroll
deductions for the purchase of shares will be made during the Offering Period.
If a participant withdraws from an Offering Period, payroll deductions will not
resume at the beginning of the succeeding Offering Period unless the participant
delivers to the Company a new subscription agreement.
                (b) Upon a participant's ceasing to be an Employee (as defined
in Section 2(g) hereof), for any reason, he or she will be deemed to have
elected to withdraw from the Plan and the payroll deductions credited to such
participant's account during the Offering Period but not yet used to exercise
the option will be returned to such participant or, in the case of his or her
death, to the person or persons entitled thereto under Section 14 hereof, and
such participant's option will be automatically terminated. The preceding
sentence notwithstanding, a participant who receives payment in lieu of notice
of termination of employment shall be treated as continuing to be an Employee
for the participant's customary number of hours per week of employment during
the period in which the participant is subject to such payment in lieu of
notice.
                 (c) A participant's withdrawal from an Offering Period will not
have any effect upon his or her eligibility to participate in any similar plan
which may hereafter be adopted by the Company or in succeeding Offering Periods
which commence after the termination of the Offering Period from which the
participant withdraws.

        11. Interest. No interest shall accrue on the payroll deductions of a
participant in the Plan.

        12. Stock.
                 (a) The maximum number of shares of the Company's Common Stock
which shall be made available for sale under the Plan shall be 1,000,000 shares,
subject to adjustment upon changes in capitalization of the Company as provided
in Section 18 hereof. If on a given Exercise Date the number of shares with
respect to which options are to be exercised exceeds the number of shares then
available under the Plan, the Company shall make a pro rata allocation of the
shares remaining available for purchase in as uniform a manner as shall be
practicable and as it shall determine to be equitable.
                 (b) The participant will have no interest or voting right in
shares covered by his option until such option has been exercised.
                 (c) Shares to be delivered to a participant under the Plan will
be issued in the name of the participant or in the name of the participant and
his or her spouse.

        13. Administration.
                 (a) Administrative Body. The Plan shall be administered by the
Board or a committee of members of the Board appointed by the Board. The Board
or its committee shall have full and exclusive discretionary authority to
construe, interpret and apply the terms of the Plan, to determine eligibility
and to adjudicate all disputed claims filed under the Plan. Every finding,
decision and determination made by the Board or its committee shall, to the full
extent permitted by law, be final and binding upon all parties.
                 (b) Rule 16b-3 Limitations. Notwithstanding the provisions of
Subsection (a) of this Section 13, in the event that Rule 16b-3 promulgated
under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or
any successor provision ("Rule 16b-3") provides specific requirements for the
administrators of plans of this type, the Plan shall be administered only by
such a body and in such a manner as shall comply with the applicable
requirements of Rule 16b-3. Unless permitted by Rule 16b-3, no discretion
concerning decisions regarding the Plan shall be afforded to any committee or
person that is not "disinterested" as that term is used in Rule 16b-3.

        14. Designation of Beneficiary.
                 (a) A participant may file a written designation of a
beneficiary who is to receive any shares and cash, if any, from the
participant's account under the Plan in the event of such participant's death
subsequent to an Exercise Date on which the option is exercised but prior to
delivery to such participant of such shares and cash. In addition, a participant
may file a written designation of a beneficiary who is to receive any cash from
the participant's account under the Plan in the event of such participant's
death prior to exercise of the option. If a participant is married and the
designated beneficiary is not the spouse, spousal consent shall be required for
such designation to be effective.


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                 (b) Such designation of beneficiary may be changed by the
participant at any time by written notice. In the event of the death of a
participant and in the absence of a beneficiary validly designated under the
Plan who is living at the time of such participant's death, the Company shall
deliver such shares and/or cash to the executor or administrator of the estate
of the participant, or if no such executor or administrator has been appointed
(to the knowledge of the Company), the Company, in its discretion, may deliver
such shares and/or cash to the spouse or to any one or more dependents or
relatives of the participant, or if no spouse, dependent or relative is known to
the Company, then to such other person as the Company may designate.

        15. Transferability. Neither payroll deductions credited to a
participant's account nor any rights with regard to the exercise of an option or
to receive shares under the Plan may be assigned, transferred, pledged or
otherwise disposed of in any way (other than by will, the laws of descent and
distribution or as provided in Section 14 hereof) by the participant. Any such
attempt at assignment, transfer, pledge or other disposition shall be without
effect, except that the Company may treat such act as an election to withdraw
funds from an Offering Period in accordance with Section 10 hereof.

        16. Use of Funds. All payroll deductions received or held by the
Company under the Plan may be used by the Company for any corporate purpose, and
the Company shall not be obligated to segregate such payroll deductions.

         17, Reports. Individual accounts will be maintained for each
participant in the Plan. Statements of account will be given to participating
Employees at least annually, which statements will set forth the amounts of
payroll deductions, the Purchase Price, the number of shares purchased and the
remaining cash balance, if any.

        18. Adjustments Upon Changes in Capitalization.
                 (a) Changes in Capitalization. Subject to any required action
by the shareholders of the Company, the Reserves as well as the price per share
of Common Stock covered by each option under the Plan which has not yet been
exercised shall be proportionately adjusted for any increase or decrease in the
number of issued shares of Common 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 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.
                 (b) Dissolution or Liquidation. In the event of the proposed
dissolution or liquidation of the Company, the Offering Period will terminate
immediately prior to the consummation of such proposed action, unless otherwise
provided by the Board.
                 (c) Merger or Asset Sale. In the event of a proposed sale of
all or substantially all of the assets of the Company, or the merger of the
Company with or into another corporation, each option under the Plan shall be
assumed or an equivalent option shall be substituted by such successor
corporation or a parent or subsidiary of such successor corporation, unless the
Board determines, in the exercise of its sole discretion and in lieu of such
assumption or substitution, to shorten the Offering Period then in progress by
setting a new Exercise Date (the "New Exercise Date") or to cancel each
outstanding right to purchase and refund all sums collected from participants
during the Offering Period then in progress. If the Board shortens the Offering
Period then in progress in lieu of assumption or substitution in the event of a
merger or sale of assets, the Board shall notify each participant in writing, at
least ten (10) business days prior to the New Exercise Date, that the Exercise
Date for his option has been changed to the New Exercise Date and that his
option will be exercised automatically on the New Exercise Date, unless prior to
such date he has withdrawn from the Offering Period as provided in Section 10
hereof. For purposes of this paragraph, an option granted under the Plan shall
be deemed to be assumed if, following the sale of assets or merger, the option
confers the right to purchase, for each share of option stock subject to the
option immediately prior to the sale of assets or merger, the consideration
(whether stock, cash or other securities or property) received in the sale of
assets or merger by holders of Common Stock for each share of Common Stock held
on the effective date of the transaction (and if such holders were offered a
choice of consideration, the type of consideration chosen by the holders of a
majority of the outstanding shares of Common Stock); provided, however, that if
such consideration received in the sale of assets or merger was not solely
common stock of the successor corporation or its parent (as defined in Section
424(e) of the Code), the Board may, with the consent of the successor
corporation, provide for the consideration to be received upon exercise of the
option to be solely common stock of the successor corporation or its parent
equal in fair market value to the per share consideration received by holders of
Common Stock and the sale of assets or merger.
         The Board may, if it so determines in the exercise of its sole
discretion, also make provision for adjusting the Reserves, as well as the price
per share of Common Stock covered by each outstanding option, in the event the
Company effects one or more reorganizations, recapitalization, rights offerings
or other increases or reductions of shares of its outstanding Common Stock, and
in the event of the Company being consolidated with or merged into any other
corporation.


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        19. Amendment or Termination.
                 (a) The Board of Directors of the Company may at any time and
for any reason terminate or amend the Plan. Except as provided in Section 18
hereof, no such termination can affect options previously granted, provided that
an Offering Period may be terminated by the Board of Directors on any Exercise
Date if the Board determines that the termination of the Plan is in the best
interests of the Company and its shareholders. Except as provided in Section 18
hereof, no amendment may make any change in any option theretofore granted which
adversely affects the rights of any participant. To the extent necessary to
comply with Rule 16b-3 or under Section 423 of the Code (or any successor rule
or provision or any other applicable law or regulation), the Company shall
obtain shareholder approval in such a manner and to such a degree as required.
                 (b) Without shareholder consent and without regard to whether
any participant rights may be considered to have been "adversely affected," the
Board (or its committee) shall be entitled to change the Offering Periods, limit
the frequency and/or number of changes in the amount withheld during an Offering
Period, establish the exchange ratio applicable to amounts withheld in a
currency other than U.S. dollars, permit payroll withholding in excess of the
amount designated by a participant in order to adjust for delays or mistakes in
the Company's processing of properly completed withholding elections, establish
reasonable waiting and adjustment periods and/or accounting and crediting
procedures to ensure that amounts applied toward the purchase of Common Stock
for each participant properly correspond with amounts withheld from the
participant's Compensation, and establish such other limitations or procedures
as the Board (or its committee) determines in its sole discretion advisable
which are consistent with the Plan.

        20. Notices. All notices or other communications by a participant to
the Company under or in connection with the Plan shall be deemed to have been
duly given when received in the form specified by the Company at the location,
or by the person, designated by the Company for the receipt thereof.

        21. Conditions Upon Issuance of Shares. Shares shall not be issued with
respect to an option unless the exercise of such option and the issuance and
delivery of such shares pursuant thereto shall comply with all applicable
provisions of law, domestic or foreign, including, without limitation, the
Securities Act of 1933, as amended, the Securities Exchange Act of 1934, as
amended, the rules and regulations 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 applicable provisions of law.

        22. 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. It shall continue in effect for a term of ten (10)
years unless sooner terminated under Section 19 hereof.



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                                   EXHIBIT A
                         CALYPTE BIOMEDICAL CORPORATION
                          EMPLOYEE STOCK PURCHASE PLAN
                             SUBSCRIPTION AGREEMENT
      Original Application                                Enrollment Date:
------                                                                   ------
      Change in Payroll Deduction Rate
------
      Change of Beneficiary(ies)
------
1. _________________________________________ hereby elects to participate in the
Calypte Biomedical Corporation Employee Stock Purchase Plan (the "Employee Stock
Purchase Plan") and subscribes to purchase shares of the Company's Common Stock
in accordance with this Subscription Agreement and the Employee Stock Purchase
Plan.
2.    I hereby authorize payroll deductions from each paycheck in the amount of
____% of my Compensation on each payday (not to exceed 10%) during the Offering
Period in accordance with the Employee Stock Purchase Plan. (Please note that no
fractional percentages are permitted.)
3.    I understand that said payroll deductions shall be accumulated for the
purchase of shares of Common Stock at the applicable Purchase Price determined
in accordance with the Employee Stock Purchase Plan. I understand that if I do
not withdraw from an Offering Period, any accumulated payroll deductions will be
used to automatically exercise my option.

4.    I have received a copy of the complete "Employee Stock Purchase
Plan." I understand that my participation in the Employee Stock Purchase Plan is
in all respects subject to the terms of the Plan. I understand that the grant of
the option by the Company under this Subscription Agreement is subject to
obtaining shareholder approval of the Employee Stock Purchase Plan.
5.    Shares purchased for me under the Employee Stock Purchase Plan should be
issued in the name(s) of (Employee or Employee and Spouse Only):_____________
6.    I understand that if I dispose of any shares received by me pursuant to
the Plan within 2 years after the Enrollment Date (the first day of the
Offering Period during which I purchased such shares), I will be treated for
federal income tax purposes as having received ordinary income at the time of
such disposition in an amount equal to the excess of the fair market value of
the shares at the time such shares were purchased by me over the price which I
paid for the shares. I hereby agree to notify the Company in writing within 30
days after the date of any disposition of shares and I will make adequate
provision for Federal, state or other tax withholding obligations, if any, which
arise upon the disposition of the Common Stock. The Company may, but will not be
obligated to, withhold from my compensation the amount necessary to meet any
applicable withholding obligation including any withholding necessary to make
available to the Company any tax deductions or benefits attributable to sale or
early disposition of Common Stock by me. If I dispose of such shares at any time
after the expiration of the 2-year holding period, I understand that I will be
treated for federal income tax purposes as having received income only at the
time of such disposition, and that such income will be taxed as ordinary income
only to the extent of an amount equal to the lesser of (1) the excess of the
fair market value of the shares at the time of such disposition over the
purchase price which I paid for the shares, or (2) 15% of the fair market value
of the shares on the first day of the Offering Period. The remainder of the
gain, if any, recognized on such disposition will be taxed as capital gain.

7.    I hereby agree to be bound by the terms of the Employee Stock Purchase
Plan. The effectiveness of this Subscription Agreement is dependent upon my
eligibility to participate in the Employee Stock Purchase Plan. 8. In the event
of my death, I hereby designate the following as my beneficiary(ies) to receive
all payments and shares due me under the Employee Stock Purchase Plan:


NAME:    (Please print)

(First)         (Middle)       (Last)
-------------------------------------


Relationship
-------------------------------------
               (Address)

EMPLOYEE NAME: (Please print)
-------------------------------------
(First)         (Middle)       (Last)
-------------------------------------


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<PAGE>
-------------------------------------

-------------------------------------
              (Address)
Employee's Social Security Number:
-------------------------------------
Employee's Address:
-------------------------------------

-------------------------------------
I UNDERSTAND THAT THIS SUBSCRIPTION AGREEMENT SHALL REMAIN IN EFFECT THROUGHOUT
SUCCESSIVE OFFERING PERIODS UNLESS TERMINATED BY ME.

Dated: ------------------------------

-------------------------------------
Signature of Employee
-------------------------------------
Spouse's Signature (If beneficiary other than spouse)



                                       37
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                                    EXHIBIT B
                         CALYPTE BIOMEDICAL CORPORATION
                          EMPLOYEE STOCK PURCHASE PLAN
               SECTION 16 INSIDER IRREVOCABLE ELECTION AND WAIVER


To: Plan Administrator
With respect to the purchase period ending___________ 19__ (the "Next Period")
under the Company's Employee Stock Purchase Plan (the "Plan") and for all future
periods, I hereby irrevocably elect:
(i)   to have amounts withheld from each of my paychecks during such period at
the rate of ___% of my compensation (as defined in the Plan) per pay period
(minimum ___% and maximum ___%); AND
(ii)  to purchase shares at the end of the period designated above with all
amounts deducted from my pay and held in my account under the Plan at the end of
such period. I hereby waive any rights that I would otherwise have under the
Plan to withdraw from, or to change my rate or amount of payroll deductions,
during such period. I understand that this election and waiver must be made
prior to the commencement of the Next Period. I further understand that this
irrevocable election may only be terminated by an irrevocable notice of
termination which takes effect at least six months after it has been made.

Signed:
--------------------------

Name:
--------------------------

Date:
--------------------------


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                                    EXHIBIT C
                         CALYPTE BIOMEDICAL CORPORATION
                          EMPLOYEE STOCK PURCHASE PLAN
                              NOTICE OF WITHDRAWAL

      The undersigned participant in the Offering Period of the Calypte
Biomedical Corporation Employee Stock Purchase Plan which began on ______ 19__
(the "Enrollment Date") hereby notifies the Company that he or she hereby
withdraws from the Offering Period. He or she hereby directs the Company to pay
to the undersigned as promptly as practicable all the payroll deductions
credited to his or her account with respect to such Offering Period. The
undersigned understands and agrees that his or her option for such Offering
Period will be automatically terminated. The undersigned understands further
that no further payroll deductions will be made for the purchase of shares in
the current Offering Period and the undersigned shall be eligible to participate
in succeeding Offering Periods only by delivering to the Company a new
Subscription Agreement.

Name and Address of Participant:
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Signature:

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Date:





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