Exhibit 5.1

                           PAULA WINNER BARNETT, ESQ.
                                 ATTORNEY AT LAW
                                17967 BORIS DRIVE
                                ENCINO, CA 91316
                                   ----------
                  Telephone 818-776-9881 Facsimile 818-743-7491
                             pwbarnett@sbcglobal.net

                                                             August 1, 2005


Calypte Biomedical Corporation
5000 Hopyard Road, Suite 480
Pleasanton, CA  94588

                                  Re: Registration Statement on Form S-8

Gentlemen:

         I have acted as counsel for Calypte Biomedical Corporation (the
"Company"), in connection with the preparation and filing of the Company's
Registration statement on Form S-8 under the Securities Act of 1933, as amended,
(the "Registration Statement"), relating to 47,000,000 shares of the Company's
common stock, $0.03 par value, (the "Common Stock") issuable under the Company's
2004 Incentive Plan, as amended and restated as of March 7, 2005 (the "Plan").

In connection with this opinion, I have examined the following records,
documents and instruments:

(a)      The Amended and Restated Certificate of Incorporation of the Company,
         as amended to date, certified by the Secretary of State of the State of
         Delaware as of July 29, 2005;

(b)      The Bylaws of the Company, as amended to date;

(c)      A certificate of good standing issued by the Secretary of State of the
         State of Delaware as of July 29, 2005.

(d)      Such records of corporate proceedings of the Company as I deemed
         appropriate for the purposes of this opinion;

(e)      An officers' certificate of the Company certifying certain factual
         matters of the Company;

(f)      A certificate from American Stock Transfer and Trust Company, the
         transfer agent of the Company, as to the number of shares of common
         stock of the Company outstanding as of July 29, 2005; and

(g)      The Plan; and

(h)      The Registration Statement and the exhibits thereto.

In addition, I have examined such records, documents, certificates of public
officials and of the Company, and considered such questions of law as I have
deemed necessary for the purpose of rendering the opinion set forth below.

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In my examination of the foregoing, I have assumed the authenticity of all
records, documents and instruments submitted to me as originals, the genuineness
of all signatures, the legal capacity of natural persons and the conformity to
the originals of all records, documents and instruments submitted to me as
certified, conformed or photostatic copies. With regard to certain factual
matters, I have relied upon statements and representations of officers of the
Company.

This opinion is limited to the federal law of the United States of America and
the General Corporation Law of the State of Delaware, including the statutory
provisions and all applicable provisions of the Delaware Constitution and
reported judicial decisions interpreting these laws.

Based upon and subject to the foregoing, and assuming that (i) the Registration
Statement becomes and remains effective during the period when the Shares are
offered, issued and sold, (ii) the Shares to be sold are issued in accordance
with the terms of the Plan, (iii) the Company receives the full consideration
for the Shares as stated in the Plan, (iv) the per share consideration for each
Share includes payment of cash or other lawful consideration at least equal to
the par value of the Company's common stock and is deemed to be fair and
reasonable consideration, and (v) all applicable securities laws are complied
with, as of the date hereof, I am of the opinion that when issued and sold by
the Company, after payment therefore in the manner provided in the agreements
which accompany the Plan, the Shares will be legally issued, fully paid and
nonassessable.

I hereby consent to being named as counsel to the Company in the Registration
Statement and to the inclusion of this opinion as an exhibit to the Registration
Statement. In giving this consent, I do not thereby admit that I am within the
category of persons whose consent is required under Section 7 of the Securities
Act or the rules and regulations of the Commission thereunder.

                                                 Very truly yours,

                                                 PAULA WINNER BARNETT, ESQ.

                                                 /s/ Paula Winner Barnett

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