Zurich and Basel, Switzerland, April 8, 2004

Prionics and Roche Gain Approval of Rapid BSE Tests from USDA

Prionics AG, the world leader in testing procedures for bovine spongiform encephalopathy (BSE), or "mad cow" disease, Roche Diagnostics, the number one in-vitro diagnostics company in the world announced today that the U.S. Department of Agriculture (USDA) has approved the two Prionics BSE tests, Prionics®-Check WESTERN, and Prionics®-Check LIA, for use in the United States' enhanced BSE surveillance program. Both tests will be distributed by Roche Diagnostics in the United States. On a world-wide basis, Roche Diagnostics has distributed the Prionics tests in most major markets since February 2001.

"Based on our extensive experience throughout the world, Prionics and Roche recommend the Prionics®-Check WESTERN test, based on the Western Blot technique, to be used for the U.S. BSE surveillance program," said Markus Moser, CEO of Prionics. "The Western Blot is known for its increased level of accuracy, because it does not produce false positive results, which can cause a significant loss in consumer confidence and have major economic impact, particularly in BSE-free countries and countries with a low incidence of BSE, like the U.S."

Prionics®-Check WESTERN was used in 18 million of the 30 million BSE tests conducted worldwide between 2001 and 2003, without false positive results.

"The licensing of our BSE test is a step forward towards a better protection of consumers from potentially BSE infected beef," said Martin Madaus, President and CEO, Roche Diagnostics. "The Prionics®-Check WESTERN kit is used throughout the world in markets concerned with BSE. The advantage of Prionics®-Check WESTERN kit is that it is the only test that did not give 'false positives' in downer cattle or any cattle population in 18 million tested samples."

"Our superior technology and our vast worldwide experience in setting up surveillance programs, optimizing logistics and establishing laboratory networks will enable Prionics and Roche to provide the U.S. with unparalleled assistance in BSE surveillance and testing," Moser added.

The Prionics®-Check LIA test is manufactured by Pierce Biotechnology Inc., Rockford, IL, USA. The Prionics®-Check WESTERN test is manufactured by Greiner Diagnostics, Langenthal Switzerland. Prionics' technology is currently used in over 30 countries throughout the world, including Canada, New Zealand, Australia and in most European countries.

About Prionics' BSE-tests
Prionics is the only BSE-test provider that offers both types of rapid test technologies, the ELISA (Prionics®-Check LIA) and the Western Blot (Prionics®-Check WESTERN). The Western Blot technique results in a fingerprint of the infectious particle that yields specific details and therefore does not produce false positive results. This is of particular importance for BSE-surveillance programs in BSE-free countries or countries with a low BSE incidence.
The Prionics®-Check LIA, based on the ELISA technology, has been the method of choice in Europe in later phases of surveillance programs in case BSE has been found to be present at a certain level.

About Prionics AG
Prionics AG has the largest number of scientists in the industry focused on BSE, and works closely with a network of prion and neurological experts around the world. Prionics' surveillance concept has led to the establishment of official EU-wide BSE screening programs in 2001, and Prionics®-Check WESTERN is the preferred test in these programs.
Prionics AG, based in Zurich, Switzerland, is an ISO 9001 certified company and currently employs 100 people. For more information about Prionics please visit www.prionics.ch.

About Roche and Roche Diagnostics
Headquartered in Basel, Switzerland, Roche is one of the world's leading innovation-driven healthcare groups. Its core businesses are pharmaceuticals and diagnostics. Roche is number one in the global diagnostics market, the leading supplier of pharmaceuticals for cancer and a leader in virology and transplantation. As a supplier of products and services for the prevention, diagnosis and treatment of disease, the Group contributes on a broad range of fronts to improving people's health and quality of life. Roche employs roughly 65,000 people in 150 countries. The Group has alliances and research and development agreements with numerous partners, including majority ownership interests in Genentech and Chugai. Roche's Diagnostics Division, the world leader in in-vitro diagnostics with a uniquely broad product portfolio, supplies a wide array of innovative testing products and services to researchers, physicians, patients, hospitals and laboratories worldwide.

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