Japanese Patent Office Upholds Enzo Biochem Patent Covering Technology for Genetic Analysis.

Business Editors, Science Writers

FARMINGDALE, N.Y.--(BUSINESS WIRE)--Aug. 7, 2000

Enzo Biochem, Inc. (NYSE:ENZ) announced today that the Japanese Patent Office in an opposition proceeding upheld Enzo's patent No. 2,825,090 that covers a key segment of the Company's gene identification technology.

The patent covers an Enzo invention that permits the direct and quantitative measurement of the intensity of any signal and thereby measuring the amount of the DNA present. The patent describes both kits and methods in which the formation of a detectable substance or "signal" in solution indicates the presence and quantity of DNA in the sample. The DNA is attached to a solid surface such as a microplate or a biochip to form an array. When treated with the Enzo reagents, a measurable signal is generated.

"We believe this patent has broad application within the rapidly-growing area of genome research and development, and represents still another significant extension of Enzo's capabilities into broader venues of medicine and science," said Elazar Rabbani, Ph.D., Chairman and CEO. "We are highly pleased with the reaffirmation of our patent by the Japanese Patent Office."

Dr. Rabbani pointed out that over the years Enzo has been awarded approximately 200 patents worldwide and that the company has a similar number of patent applications pending. "This vast patent estate is a major Enzo asset, allowing the Company to play an increasingly important role in the rapidly unfolding world of modern day diagnostics and genomics. It is just one aspect of the Company's many strengths," he said. "Upholding of this patent in Japan further validates our extensive and increasingly rewarding research and development efforts conducted over the past two decades and which remains ongoing."

Enzo Biochem is engaged in the research, development and manufacture of innovative health care products based on molecular biology and genetic engineering techniques, and in providing diagnostic serves to the medical community. The Company has approximately 200 patents worldwide, many of which cover proprietary labeling and detection products for gene sequencing and genetic analysis and are sold to the life science market throughout the world. The Company's therapeutic division currently is conducting two human clinical trials, one for HIV infected patients, and one for patients infected with hepatitis B virus. Other potential future therapeutic applications of Enzo's proprietary technologies are directed towards cholesterol management and the treatment of inflammatory bowel disease, including Crohn's disease and ulcerative colitis. The Company also holds a patent covering a method and materials for correcting point mutations or small insertions or deletions of genetic material, which would allow for editing and correcting certain abnormalities in genes.

Except for historical information, the matters discussed in this news release may be considered "forward-looking" statements with the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, As amended. Such statements include declarations regarding the intent, belief or curre3nt expectations of the Company and its management. Prospective investors are cautioned that any such forward-looking statements are not guarantees of future performance and involve a number of risks and uncertainties that could materially affect actual results.