Document:

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                                                                  Exhibit 10.72
                          LOAN MODIFICATION AGREEMENT

         This Loan Modification Agreement is entered into as of May 24, 2000, by
and between Calypte Biomedical Corporation (the "Borrower") and Silicon Valley
Bank ("Bank").

1.       DESCRIPTION OF EXISTING INDEBTEDNESS: Among other indebtedness which
may be owing by Borrower to Bank, Borrower is indebted to Bank pursuant to,
among other documents, a Loan and Security Agreement, dated December 21, 1998,
as may be amended from time to time, (the "Loan Agreement"). The Loan Agreement
provided for, among other things, a Committed Line in the original principal
amount of Two Million Dollars ($2,000,000). Defined terms used but not otherwise
defined herein shall have the same meanings as in the Loan Agreement.

Hereinafter, all indebtedness owing by Borrower to Bank shall be referred to as
the "Indebtedness."

2.       DESCRIPTION OF COLLATERAL AND GUARANTIES. Repayment of the Indebtedness
is secured by the Collateral as described in the Loan Agreement.

Hereinafter, the above-described security documents and guaranties, together
with all other documents securing repayment of the Indebtedness shall be
referred to as the "Security Documents". Hereinafter, the Security Documents,
together with all other documents evidencing or securing the Indebtedness shall
be referred to as the "Existing Loan Documents".

3.       DESCRIPTION OF CHANGE IN TERMS.

                  A.       MODIFICATION(S) TO LOAN AGREEMENT.

                  1.       The following Section 2.1.1 entitled "Cash Management
                           Facility" is hereby incorporated to read as follows:

                           2.1.1 Cash Management Facility. Until May 24, 2001,
                           Borrower may use up to $12,000 for Bank's Cash
                           Management Services, which may include merchant
                           services, direct deposit of payroll, business credit
                           card, and check cashing services identified in
                           various cash management services agreements (the
                           "Cash Management Services").

                  2.       Notwithstanding the terms and conditions contained in
                           Section 2.1 entitled "Term Loan," Bank will make
                           available to Borrower one Additional Term Advance in
                           an amount not to exceed Two Hundred Fifty Thousand
                           Dollars ($250,000) for the purpose of one time
                           purchase of Equipment (the "Second Additional Term
                           Advance").

                           The sum of (a) the Second Additional Term Advance and
                           (b) the remaining aggregate Term Advances including
                           the Additional Term Advance shall be repaid in equal
                           monthly installments of principal, plus accrued
                           interest, beginning on the 20th of each month and
                           continuing on the same day thereafter until the Term
                           Maturity Date, when all unpaid balance and accrued
                           interest shall be due and payable.

                  3.       Section 4.5 entitled "Cash Collateral" is hereby
                           amended to read as follows:

                           Upon Borrower's failure to comply with one or more of
                           the financial covenants in Sections 6.8, 6.9 or 6.10,
                           an Event of Default shall not be deemed to have
                           occurred, provided that Bank places a hold on a
                           Silicon Valley Bank certificate of deposit in the
                           name of Borrower in an amount not less than 105% of
                           the then outstanding Obligations.

                                       1

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                  4.       Section 6.12 entitled "Compensating Balances" is
                           hereby incorporated to read as follows:

                           Borrower shall maintain an amount equal to or greater
                           than the current outstanding Obligations in Bank's
                           money market account or Bank's Investment Product and
                           Services Group account or any other Bank's account
                           approved by Bank. Borrower's failure to comply with
                           this Section 6.12 shall be deemed an Event of
                           Default.

4.       CONSISTENT CHANGES. The Existing Loan Documents are hereby amended
wherever necessary to reflect the changes described above.

5.       PAYMENT OF LOAN FEE. Borrower shall pay to Bank a fee in the amount
of Two Hundred Fifty Dollars ($250) (the "Loan Fee") plus all out-of-pocket
expenses.

6.       NO DEFENSES OF BORROWER. Borrower (and each guarantor and pledgor
signing below) agrees that, as of the date hereof, it has no defenses against
the obligations to pay any amounts under the Indebtedness.

7.       CONTINUING VALIDITY. Borrower (and each guarantor and pledgor signing
below) understands and agrees that in modifying the existing Indebtedness,
Bank is relying upon Borrower's representations, warranties, and agreements,
as set forth in the Existing Loan Documents. Except as expressly modified
pursuant to this Loan Modification Agreement, the terms of the Existing Loan
Documents remain unchanged and in full force and effect. Bank's agreement to
modifications to the existing Indebtedness pursuant to this Loan Modification
Agreement in no way shall obligate Bank to make any future modifications to
the Indebtedness. Nothing in this Loan Modification Agreement shall constitute
a satisfaction of the Indebtedness. It is the intention of Bank and Borrower
to retain as liable parties all makers and endorsers of Existing Loan
Documents, unless the party is expressly released by Bank in writing. No
maker, endorser, or guarantor will be released by virtue of this Loan
Modification Agreement. The terms of this paragraph apply not only to this
Loan Modification Agreement, but also to all subsequent loan modification
agreements.

8.       CONDITIONS. The effectiveness of this Loan Modification Agreement is
conditioned upon Borrower's payment of the Loan Fee.

         This Loan Modification Agreement is executed as of the date first
written above.

BORROWER:                                         BANK:

CALYPTE BIOMEDICAL CORPORATION                    SILICON VALLEY BANK

By: /s/ Nancy E. Katz                             By: /s/ Raed Y. AlFayoumi
   -------------------------                         ---------------------------
Name: Nancy E. Katz                               Name: Raed Y. AlFayoumi
     -----------------------                           -------------------------
Title: President/COO/CFO                          Title: Vice President
      ----------------------                            ------------------------<PAGE>

                                                                  Exhibit 10.73

                    FOURTH AMENDMENT TO THE LICENSE AGREEMENT

                                      BETWEEN

              NEW YORK UNIVERSITY AND CALYPTE BIOMEDICAL CORPORATION

This Fourth Amendment to Agreement (hereafter "Amendment") is effective on
June 1, 2000 by and between CALYPTE Biomedical Corporation, a corporation
organized and existing under the laws of Delaware, having a place of business
at 1265 Harbor Bay Parkway, Alameda, California 94502 (hereafter
"CORPORATION"); and NEW YORK UNIVERSITY, a corporation organized and existing
under the laws of the State of New York, having a place of business at 70
Washington Square South, New York, New York 10012 (hereafter "NYU").

                                    WITNESSETH:
                                    -----------

        WHEREAS, CORPORATION and NYU entered into a certain agreement made
and effective as of August 12, 1993 (the "License Agreement"), pursuant to
which, INTER ALIA, NYU granted to CORPORATION certain rights to certain
inventions relating to the detection of antibodies to human immunodeficiency
virus (HIV) in urine, and the parties agreed to certain other related matters
as specified herein; and

        WHEREAS, The License Agreement has been amended from time to time in
the past (the "Amended License Agreement"); and

        WHEREAS, CORPORATION and NYU wish to modify certain terms and
conditions of the Amended License Agreement as specified herein;

        NOW, THEREFORE, in consideration of the premises and the covenants,
conditions and promises set forth below, the parties hereto hereby agree as
follows:

        1.   Except as expressly provided for herein, all terms and
             conditions of the Amended License Agreement shall remain in full
             force and effect.

[*] 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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        2.   Terms which are defined in the Amended License Agreement shall
             have the same meanings when used in this Amendment, unless a
             different definition is given herein.

        3.   [*]

[*] 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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             [*]

        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.   A new Section 6.e. shall be added to the License Agreement and
             shall read as follows:

             e.   [*]

[*] 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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        6.   A new Section 6.f. shall be added to the License Agreement and
             shall read as follows:

             f.   [*]

[*] 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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IN WITNESSETH WHEREOF, the parties hereto have executed this Fourth Amendment
as follows:

NEW YORK UNIVERSITY                     CALYPTE BIOMEDICAL CORPORATION

BY:     /s/ Isaac T. Kohlberg           BY:      /s/ Nancy E. Katz
      ------------------------------           ------------------------------

NAME:   Isaac T. Kohlberg               NAME:    Nancy E. Katz
      ------------------------------           ------------------------------

TITLE:  Vice Dean for Industrial        TITLE:   CEO/President/CFO
      ------------------------------           ------------------------------
        Liason and Research Administration

DATE:   6//20/00                        DATE:    6/19/00
      ------------------------------           ------------------------------

[*] 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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