Calypte Implements Reverse Stock Split; $15 Billion Emergency Plan for AIDS Relief Signed by President Bush.

Business Editors/Health/Medical Writers

ALAMEDA, Calif.--(BUSINESS WIRE)--May 28, 2003

Calypte Biomedical Corporation (OTCBB:CALY), the developer and marketer of the only two FDA approved HIV-1 antibody tests that can be used on urine samples, as well as an FDA approved serum HIV-1 antibody Western blot supplemental test, announced that it has been informed by the Over the Counter Bulletin Board (OTCBB) that its common stock, following the 1:30 reverse stock split approved by its stockholders on May 20, 2003, will trade temporarily under the symbol CYPTV beginning today. Calypte expects that its common stock will ultimately trade on the OTCBB under the symbol CYPT. The new stock symbol and post-split trading will be effective at the opening of the OTCBB on Wednesday, May 28, 2003.

"This restructuring is the cornerstone of our ongoing plans to add value and growth, that along with our government initiatives, we believe will allow us to utilize such opportunities as the Emergency Plan for AIDS Relief signed yesterday, which provides for significant prevention efforts, including voluntary testing and counseling," said Anthony Cataldo, Executive Chairman of Calypte Biomedical.

"Calypte, along with many other companies and organizations in the U.S. and abroad, are committed to helping the most HIV/AIDS afflicted countries around the globe."

About Calypte Biomedical:

Calypte Biomedical Corporation headquartered in Alameda, California, is a public healthcare company dedicated to the development and commercialization of urine-based diagnostic products and services for Human Immunodeficiency Virus Type 1 (HIV-1), sexually transmitted diseases and other infectious diseases. Calypte's tests include the screening EIA and supplemental Western Blot tests, the only two FDA-approved HIV-1 antibody tests that can be used on urine samples. The company believes that accurate, non-invasive urine-based testing methods for HIV and other infectious diseases may make important contributions to public health by helping to foster an environment in which testing may be done safely, economically, and painlessly. Calypte markets its products in countries worldwide through international distributors and strategic partners. Current product labeling including specific product performance claims can be found at www.calypte.com.

Statements in this press release that are not historical facts are forward-looking statements, including statements regarding announcements of financial results and presentations by the Company. Such statements reflect management's current views, are based on certain assumptions and involve risks and uncertainties. Actual results, events, or performance may differ materially from the above forward-looking statements due to a number of important factors, and will be dependent upon a variety of factors, including, but not limited to, our ability to obtain additional financing that will allow us to continue our current and future operations and whether demand for our product and testing service in domestic and international markets will continue to expand. The Company undertakes no obligation to publicly update these forward-looking statements to reflect events or circumstances that occur after the date hereof or to reflect any change in the Company's expectations with regard to these forward-looking statements or the occurrence of unanticipated events. Factors that may impact the Company's success are more fully disclosed in the Company's most recent public filings with the U.S. Securities and Exchange Commission ("SEC"), including its annual report on Form 10-K for the year ended December 31, 2002 and its subsequent filings with the SEC.