HERCULES, CA — December 4, 2002 — Bio-Rad Laboratories, Inc. (AMEX: BIO and BIO.B), a multinational manufacturer and distributor of life science research products and clinical diagnostics, announced today that the United States Department of Agriculture (USDA) has revised the company’s existing veterinary biological permit for its rapid test used for the detection of chronic wasting disease (CWD). It is now possible for all USDA-approved laboratories to conduct comprehensive CWD surveillance programs using the Bio-Rad CWD test on white-tailed deer and elk, as well as mule deer. Whitetailed deer are the most widely hunted species in the United States. In November, the Bio-Rad test was approved for use on mule deer. Since then, further validation studies were conducted primarily by the Colorado State University Veterinary Diagnostic Laboratory, with contributions from the Wisconsin and Wyoming state veterinary diagnostic laboratories and the USDA. These studies led to the expanded USDA approvals. “We have continued to work closely with the USDA and state diagnostic labs to complete the validation process for our CWD test, and we now welcome the opportunity to provide all government-authorized laboratories with a complete solution for their CWD screening and surveillance programs,” said Norman Schwartz Bio-Rad vice president and manager of Life Science.

Bio-Rad’s rapid CWD test is a highly efficient procedure for screening large numbers of samples. Results are generated in just five hours, compared to the classical IHC (immunohistochemistry) method which can take up to five days. The Bio-Rad CWD test is the latest in a series of tests used for the detection of TSEs (transmissible spongiform encephalopathies). These tests have become the industry standard in rapid testing due to their speed, sensitivity, accuracy and ease-of-use.

Bio-Rad Laboratories, Inc. (www.bio-rad.com) is a multinational manufacturer and distributor of life science research products and clinical diagnostics. It is based in Hercules, California, and serves more than 70,000 research and industry customers worldwide through a network of more than 30 wholly owned subsidiary offices. Various statements made within this press release may constitute “forward-looking statements” for purposes of the Securities and Exchange Commission’s “safe harbor” provisions under the Private Securities Litigation Reform Act of 1995 and Rule 3b-6 under the Securities Exchange Act of 1934. The forward-looking statements contained herein involve risks and uncertainties that could cause results to differ materially from the Company’s expectations. For more information, contact: Ron Hutton, Treasurer Bio-Rad Laboratories, Inc. (510) 724-7000 [email protected] Roger Villareal Benjamin | Weber Shandwick (415) 352-2628 [email protected]