Johnson and Johnson first customer for Affymetrix new 96-well high-throughput GeneChip array platform

Santa Clara, Calif., Sept. 24, 2003 -- Affymetrix, Inc., (NASDAQ: AFFX) today announced that Johnson & Johnson Pharmaceutical Research & Development, L.L.C. (J&JPRD) is the first company to gain early access to the new GeneChip^® HighThroughputArray (HTA) Human Genome U133 Array, a standard 96-well plate which will have a GeneChip^® Human Genome U133 A array in each well.

“Over a decade ago we launched GeneChip technology to change the way researchers examine the genome,” said Stephen P.A. Fodor, Ph.D., Chairman and Chief Executive of Affymetrix. “Today we are introducing a new 96-well format to industrialize GeneChip genome research. This new format is designed to speed drug development, reduce costs and help scientists produce more effective, targeted therapies. J&JPRD’s leadership in leveraging genomics to improve human life is well known. We’re delighted they’re our first partner in this industrial format for our GeneChip technology.”

The GeneChip HTA system will have the capacity to process hundreds of biological samples per day with minimal human supervision, reducing capital, labor, reagent and array expenses. The GeneChip HTA system adapts the same industry-standard GeneChip technology and content that Affymetrix uses in its cartridges to a standard 96-well microtiter plate, which runs on an automated system built with off-the-shelf robotic components. The GeneChip HTA system automates the most labor intensive steps in GeneChip processing, dramatically reducing the cost per assay. The decrease in cost and increase in throughput makes the GeneChip HTA system well suited for downstream development applications like compound profiling, toxicology and clinical trials.

The components that Affymetrix will provide for the GeneChip HTA system include the HTA 96-well plate, the automated assay derived from Affymetrix’ standard gene expression assay, and a software system for tracking samples and data.

About Affymetrix:

Affymetrix is a pioneer in creating breakthrough tools that are driving the genomic revolution. By applying the principles of semiconductor technology to the life sciences, Affymetrix develops and commercializes systems that enable scientists to improve the quality of life. The Company's customers include pharmaceutical, biotechnology, agrichemical, diagnostics and consumer products companies as well as academic, government and other non-profit research institutes. Affymetrix offers an expanding portfolio of integrated products and services, including its integrated GeneChip platform, to address growing markets focused on understanding the relationship between genes and human health. Additional information on Affymetrix can be found at www.affymetrix.com.

All statements in this press release that are not historical are "forward-looking statements" within the meaning of Section 21E of the Securities Exchange Act as amended, including statements regarding Affymetrix' "expectations," "beliefs," "hopes," "intentions," "strategies" or the like. Such statements are subject to risks and uncertainties that could cause actual results to differ materially for Affymetrix from those projected, including, but not limited to risks of the Company's ability to achieve and sustain higher levels of revenue, higher gross margins, reduced operating expenses, uncertainties relating to technological approaches, manufacturing, product development, market acceptance (including uncertainties relating to product development and market acceptance of the GeneChip HighThroughputArray format), personnel retention, uncertainties related to cost and pricing of Affymetrix products, dependence on collaborative partners, uncertainties relating to sole source suppliers, uncertainties relating to FDA and other regulatory approvals, competition, risks relating to intellectual property of others and the uncertainties of patent protection and litigation. These and other risk factors are discussed in Affymetrix' Form 10-K for the year ended December 31, 2002 and other SEC reports, including its Quarterly Reports on Form 10-Q for subsequent quarterly periods. Affymetrix expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in Affymetrix' expectations with regard thereto or any change in events, conditions, or circumstances on which any such statements are based. 

NOTE: Affymetrix, the Affymetrix logo, and GeneChip and are registered trademarks owned or used by Affymetrix, Inc.

For further information, please contact:

Sue Charles, CEO Northbank Communications, +44 (0)7886 8152, s.charles@northbankcommunications.com

Wes Conard, Senior Manager of Public Relations, +1 (0)408 731 5791