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                                                                   Exhibit 10.77

                        TEMPORARY DISTRIBUTION AGREEMENT

Whereas Calypte Biomedical Corporation ("Calypte") and American Edge Medical
Company ("American Edge") executed in May, 2000 a Distribution Agreement whereby
Calypte appointed American Edge as its exclusive distributor for Calypte
products in the Republic of South Africa (the "Distribution Agreement"), and

Whereas the two parties wish to explore the possibility of extending the
Territory governed by the Distribution Agreement beyond the Republic of South
Africa, to include forty-one additional sub-Saharan African countries, the
parties agree as follows:

The Temporary Distribution Agreement Territory shall include the forty-one
sub-Saharan countries south of, and including Mauritania, Mali, Niger, Chad,
Eritrea, Djibouti, and Somalia. The island of Madagascar is also included. The
Republic of South Africa is excluded from this Temporary Distribution Agreement
since it is already governed by a the Distribution Agreement.

Effective August 1, 2000 and until January 31, 2001 inclusive, Calypte shall
grant to American Edge on a temporary basis the exclusive distribution rights
for the products itemized in the Distribution Agreement, with inter alia, the
following five provisions:

1.   [*]

2.   American Edge shall not sub-distribute Calypte products through any party
     other than African Medical Solutions without the prior express written
     approval of Calypte.

3.   American Edge shall ensure, both through its own actions and those of
     African Medical Solutions and its partners, that Calypte's products are
     always portrayed accurately in terms of clinical performance, product
     storage requirements, laboratory requirements, and sampling requirements.

4.   [*]

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS

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5.   All terms and definitions of the Distribution Agreement governing the
     Republic of South Africa shall apply to the Temporary Distribution
     Agreement and are hereby incorporated by reference, except for those
     relating specifically to South African sales minima and termination date.
     American Edge specifically agrees to abide by Clause 4.16 of the South
     Africa Distribution Agreement regarding competing products with respect to
     this Temporary Distribution Agreement.

Between January 15 and January 31, 2001, provided that American Edge has
complied with the five provisions above and the applicable terms and conditions
of the Distribution Agreement, Calypte and American Edge, in concert with
American Edge's sub-distributor African Medical Solutions, will review the sales
prospects for each of the forty-one countries in the Temporary Distribution
Agreement. At that time, Calypte, in good faith, will determine if the Temporary
Distribution Agreement shall be extended, and under what terms and minima.
Depending on the outcome of these discussions, an extension may be granted for
none, some, or all of the forty-one countries.

In the event that American Edge fails to comply with any of the five provisions
above or the applicable terms and conditions of the Distribution Agreement,
Calypte may choose not to extend the Temporary Distribution Agreement
whatsoever. In this event, effective February 1, 2001 Calypte will be free to
appoint any distributor(s) it chooses, for any or all of the countries within
the territory governed by this Temporary Distribution Agreement.

Agreed upon, this 21 day of July, 2000

By:

/s/ Nancy E. Katz                           /s/ Sammy Ciling
----------------------------------          ----------------------------------
Nancy Katz, President and CEO               Sammy Ciling, President
Calypte Biomedical Corporation              American Edge Medical Company

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS<PAGE>

                                                                   Exhibit 10.78

                   [Calypte Biomedical Corporation Letterhead]

                                October 17, 2000

John J. DiPietro
5615 Morningside Drive
San Jose, CA  95138

         Re:      EXTENSION OF YOUR CONSULTING AGREEMENT WITH CALYPTE

Dear John:

         Upon your signature at the end of this letter where indicated, this
letter will be a binding amendment to extend (the "EXTENSION") the Consulting
Agreement between Calypte Biomedical Corporation ("CALYPTE") and you dated as of
September 17, 1999 (the "CONSULTING AGREEMENT"), with respect to your provision
of service as a consultant to Calypte as provided in this letter (the services
described in Section 1 hereof are referred to herein as the "SERVICES"). This
Extension shall be effective as of September 17, 2000 (the "EFFECTIVE DATE").
With the exception of the sections amended in their entirety below, all other
sections of the Agreement will remain in effect until the termination of this
Extension.

         1.       SERVICES.

                  (a) UPDATE TO LIST OF BASIC SERVICES; - AMENDMENT OF SECTION
1(A) OF THE CONSULTING AGREEMENT Subject to the terms and conditions of the
Consulting Agreement, you shall continue to be retained by Calypte as a
consultant to Calypte until terminated as provided herein, to provide up to an
aggregate of sixteen (16) hours of Services per calendar month during the term
hereof (or such additional hours as you may agree with Calypte as provided in
Section 1(b) hereof), with travel time counted as one-half time (I.E., one hour
of travel time will be counted as one-half hour of time spent consulting
hereunder), with respect to (i) financial and operational matters and projects
relating to Calypte's current and/or future products, (ii) assisting in the
selection, recruitment and integration with Calypte of a Chief Financial
Officer, (iii) assisting in the selection of a distributor for Calypte products
in India; and (iv) assisting in the raising of additional capital funds for
Calypte, all as may be requested from time to time during the term hereof orally
or in writing by an officer (President, Chief Executive Officer, Chief Financial
Officer, Vice President) or member of the Board. The number of hours spent by
you hereunder as rendering Services to Calypte will be in addition to time you
spend to discharge your customary duties as a Director of Calypte, including
time to prepare for and attend meetings of the Board and of Board Committees
upon which you serve, during such time as you are serving as a Director of
Calypte. You will not receive any compensation hereunder for your services as a
Director of Calypte, but will be entitled to such indemnification, stock, and/or
stock

<PAGE>

John J. DiPietro
September 22 1999 [SIC]
Page 2

options and other benefits from the Company as are made available from time to
time by the Company to other Directors.

                  (b) - (e) No Change. These Sections shall remain in effect as
set forth in the Consulting Agreement until the termination of this Extension.

         2.       COMPENSATION AND EXPENSES.

                  (a) NO CASH COMPENSATION; CESSATION OF VESTING OF OPTION;
FURTHER AMENDMENT OF SECTION 8 OF EMPLOYMENT AGREEMENT WITH RESPECT TO SEVERANCE
PAY AND CONTINUED VESTING OF OPTION. Calypte will pay no cash amount to you for
your services rendered under this Agreement. Instead, Calypte and you hereby
agree, pursuant to Section 8 of the Employment Agreement dated as of October 28,
1998 between you and Calypte (the "EMPLOYMENT AGREEMENT"), that Section 7(d) of
your Employment Agreement, which was amended pursuant to Section 2(a) of the
Consulting Agreement, hereby is further amended to read as follows, effective as
of the day before the Effective Date; except as herein amended, neither your
Employment Agreement nor such options referred to in said section are amended:

                  "The Executive may voluntarily terminate his employment at any
         time beginning July 1, 1999, in which event he shall receive severance
         pay of Fifty-Five Thousand Dollars ($55,000.00). If in connection with
         the Executive's voluntary termination of employment hereunder, the
         Executive and the Company enter into a written agreement under which
         the Executive is to render consulting services to the Company, then
         from and after the date of such voluntary termination, vesting
         (exerciseability) of Executive's currently outstanding incentive stock
         option from the Company which was originally granted to Executive on
         October 27, 1998, for a total of 300,000 shares of Common Stock of the
         Company, originally vesting over a 24-month period beginning October
         27, 1998, at the rate of 12,500 shares per month, will not cease and
         such option is hereby amended to provide that it shall continue after
         such termination date to vest (become exerciseable) at the rate of four
         thousand (4,000) shares at the end of each monthly anniversary of the
         date of such termination, through the earlier of the date of
         termination of such consulting agreement or the twelfth (12th) monthly
         anniversary of the date of such termination. Following the twelfth
         (12th) monthly anniversary of the date of such termination, the vesting
         of such option shall cease, even if Executive continues to render
         consulting services. In addition, if in connection with any other
         Calypte stock option plan or grant, other than a plan or grant provided
         to directors of Calypte, Executive has any obligation that requires
         Executive to exercise an option to purchase Calypte stock within a
         specific period of time, such period of time will not begin until the
         date of termination of the Extension to the Consulting Agreement with
         Calypte dated as of September 17, 2000."

<PAGE>

John J. DiPietro
September 22 1999 [SIC]
Page 3

                  (b) No Change. This Section shall remain in effect as set
forth in the Consulting Agreement until the termination of this Extension.

         Sections 3 - 6. NO CHANGE These Sections shall remain in effect as set
forth in the Consulting Agreement until the termination of this Extension.

         7.       TERM OF SERVICE; TERMINATION; EFFECT OF TERMINATION.

                  (a) TERM OF SERVICE; TERMINATION. This Extension is for a
period of twelve (12) months from and after the Effective Date, subject to
earlier termination as provided in Section 7(b) hereof.

                  (b) & (c) No Change. This Section shall remain in effect as
set forth in the Consulting Agreement until the termination of this Extension.

         Sections 8 & 9. NO CHANGE These Sections shall remain in effect as set
forth in the Consulting Agreement until the termination of this Extension.

         We look forward to continuing to work with you, as a consultant, as
part of our team for the success of Calypte.

                                    Sincerely,

                                    /s/ Nancy E. Katz
                                    --------------------------------------------
                                    Nancy Katz
                                    President, Chief Executive Officer and Chief
                                    Financial Officer

ACCEPTED AND AGREED:

/s/ John DiPietro
----------------------------------------------
         John J. DiPietro
Date signed:  October 25, 2000

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