Invitrogen Signs Definitive Agreement to Acquire BioSource International; Deal Strengthens Proteomics Franchise and Positions the Company to Enter New Markets

Business Wire, July 26, 2005

CARLSBAD, Calif. -- Invitrogen Corporation (Nasdaq:IVGN) today announced the signing of a definitive agreement to acquire publicly held life sciences company BioSource International (Nasdaq:BIOI) in an all-cash transaction totaling approximately $130 million. The transaction is subject to customary closing conditions, including regulatory approval and the approval of BioSource stockholders. The transaction is expected to close by the end of the year.

This deal augments Invitrogen's growing collection of protein and primary antibody products gained through its recent acquisitions of Zymed Laboratories and Caltag Laboratories. Additionally, it bolsters Invitrogen's offerings in both kinase and cytokine assay technologies for research applications and provides the company an opportunity to enter new markets in immunology, oncology and neurodegenerative disease.

"The acquisition of BioSource enables our company to continue its growth in the vital area of proteomics," said Gregory T. Lucier, Chairman and CEO of Invitrogen Corporation. "Moreover, the potential combination of BioSource's strength in technology development and our leading brand positions us to achieve an important goal of developing a collection of disease specific tools."

BioSource International boasts a wide collection of proteins, primary and secondary antibodies, and reagents for single and multiplex cytokine and signal transduction assays. BioSource employs more than 240 people around the world. The company has a history of innovation, including several first-to-market technologies and the introduction of more than 200 new products per year since 2001.

Invitrogen expects the transaction to have no impact on 2005 pro forma earnings per share, and to be accretive by $.04 in 2006.

Conference Call:

Invitrogen will be holding a conference call to discuss details of this transaction on Tuesday, July 26, 2005 at 9:30 a.m. Pacific Time. On the call will be Lucier, Chief Financial Officer David Hoffmeister, Vice President of Investor Relations Adam Taich and BioSource President and CEO Terrance J. Bieker.

The conference call will be webcast live over the Company's investor relations website at www.invitrogen.com and will be archived at the site for one month.

Call-in information is as follows:

Toll-free (U.S.) 1-800-510-9834
Toll (International)  1-617-614-3669
Passcode: 94813357

A replay of the call will also be available by calling 1-888-286-8010 or 1-617-801-6888 and using passode 47260654. The replay will be available until August 2, 2005.

About the Company

Invitrogen Corporation (Nasdaq:IVGN) provides products and services that support academic and government research institutions and pharmaceutical and biotech companies worldwide in their efforts to improve the human condition. The company provides essential life science technologies for disease research, drug discovery and commercial bio-production. Invitrogen's own research and development efforts are focused on breakthrough innovation in all major areas of biological discovery, including functional genomics, proteomics, bio-informatics and cell biology, placing Invitrogen's products in nearly every major laboratory in the world. Founded in 1987, Invitrogen is headquartered in Carlsbad, Calif., and conducts business in more than 70 countries around the world. The company globally employs approximately 4,500 scientists and other professionals, and had revenues in excess of $1 billion in 2004. Information about Invitrogen is available on the Web at www.invitrogen.com.

Safe Harbor/Forward Looking Statements

Certain statements contained in this press release are considered "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, and it is Invitrogen's intent that such statements be protected by the safe harbor created thereby. Forward-looking statements include, but are not limited to: 1) Invitrogen will acquire BioSource International, Inc. in an-all cash transaction totaling $130 million; 2) The acquisition positions Invitrogen closer to patients; 3) The acquisition will combine BioSource's product portfolio into Invitrogen's offerings; 4) The transaction will have no impact on Invitrogen's 2005 pro forma earnings per share and accretive by $.04 in 2006. Potential risks and uncertainties include, but are not limited to, the risks: a) Customary closing conditions, shareholder votes and regulatory approvals; b) Invitrogen's business strategy is subject to change; c) Invitrogen may choose to keep the product portfolios separate; d) Actual financial results of the deal may vary from projections, as well as other risks and uncertainties detailed from time to time in Invitrogen's Securities and Exchange Commission filings.