Charles River Laboratories and Proteome Systems Ltd Launch Proteomic Services; Open House To Feature State-of-the Art Laboratory.

Business Editors/Health/Medical Writers

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WILMINGTON, Mass.--(BUSINESS WIRE)--April 3, 2003

Charles River Laboratories International, Inc. (NYSE:CRL) and Proteome Systems Ltd. are pleased to announce the opening of a new contract laboratory dedicated to proteomic research services. Charles River Proteomic Services, Inc. will celebrate the grand opening of the Worcester, Massachusetts-based facility with an Open House on April 29.

Charles River Proteomic Services offers leading-edge proteomic research services on a fee-for-service, contract basis to pharmaceutical and biotechnology clients around the world. The tools of proteomic research assist scientists in understanding the mechanisms of protein function. With that understanding, the effectiveness of a potential new drug compound can be optimized before it reaches human clinical trials.

The joint venture, announced in October 2002, operates from Charles River's Discovery and Development Services facility in Worcester, Massachusetts, close to Proteome Systems' base of US operations in Woburn, Massachusetts. Charles River Laboratories maintains an 80% ownership position in the joint venture.

Proteomic research applies a wide variety of technologies and bioinformatic tools to study the expression of proteins in the biochemical or biological context of an organism. By improving the understanding of the role proteins play in systems biology, scientists hope to be able to design safer and more effective drugs, novel therapeutics, or diagnostics and biomarkers, in a shorter period of time.

About Charles River Laboratories

Charles River Laboratories, based in Wilmington, Massachusetts, is a leading provider of critical research tools and integrated support services that enable innovative and efficient drug discovery and development. The Company is the global leader in providing the animal research models required in research and development for new drugs, devices and therapies. The Company also offers a broad and growing portfolio of biomedical products and services that enable customers to reduce cost, increase speed, and enhance productivity and effectiveness in drug discovery and development. Charles River's customer base spans over 50 countries, and includes all of the major pharmaceutical companies, biotechnology companies, and many leading hospitals and academic institutions. The Company operates 82 facilities in 16 countries worldwide. For more information, visit the Company's web site at www.criver.com.

About Proteome Systems

Proteome Systems is a leading proteomics technology, diagnostics and discovery company. With its technology partners, Proteome Systems has developed and commercialized a comprehensive solution for high throughput proteomics, which is available as a total solutions package, ProteomIQ. These technologies, integrated by a proprietary and sophisticated bioinformatics system, BioinformatIQ, are being marketed as part of a global strategic alliance with IBM. ProteomIQ is implemented in Proteome Systems' discovery programs in the areas of cystic fibrosis, cancer, infectious disease and aging. Proteome Systems has R&D and manufacturing in Sydney, Australia and Boston, USA, and a joint venture (Proteome Systems Japan) with Itochu Corporation in Tokyo, Japan. For more information about Proteome Systems, please visit the website at www.proteomesystems.com.

Caution Concerning Forward-Looking Statements. This document includes "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by the use of words such as "anticipate," "believe," "expect," "estimate," "plan," and "project" and other similar expressions that predict or indicate future events or trends or that are not statements of historical matters. These statements are based on management's current expectations, and involve a number of risks and uncertainties that could cause actual results to differ materially from those stated or implied by the forward-looking statements, and the company expressly does not undertake any duty to update forward-looking statements, which speak only as of the date of this document. Those risks and uncertainties include, but are not limited to: acquisition integration risks; special interest groups; contaminations; industry trends; new displacement technologies; outsourcing trends; USDA and FDA regulation; changes in law; continued availability of products and supplies; loss of key personnel; interest rate and foreign currency exchange rate fluctuations; changes in generally accepted accounting principles; and any changes in business, political, or economic conditions due to the threat of future terrorist activity in the U.S. and other parts of the world, and related U.S. military action overseas. A further description of these risks, uncertainties, and other matters can be found in the Risk Factors detailed in the Company's Annual Report on Form 10-K as filed on March 20, 2003, with the Securities and Exchange Commission.