Affymetrix Announces Major Genotyping Project With Kaiser Permanente and the University of California at San Francisco for NIH-Funded Epidemiology Study – 100,000-Sample Study to Be Performed Using New Axiom™ Genotyping Solution

SANTA CLARA, Calif.–Affymetrix, Inc. (Nasdaq:AFFX) today announced that the Kaiser Permanente Research Program on Genes, Environment, and Health (RPGEH) and the University of California at San Francisco (UCSF) have entered into an agreement with Affymetrix to support genome-wide analyses of DNA samples from 100,000 Kaiser Permanente members.

The members have volunteered for a large-scale research program designed to create a new resource for studying disease, health, and aging. Scientists from the program will use the just-launched Axiom Genotyping Solution, which delivers high-throughput, automated technology and enables researchers to find novel and common genetic variations associated with complex disease.

DNA studies will be linked to Kaiser Permanente’s electronic health record system, the largest of its kind. Information from health surveys and environmental data will also be analyzed. These resources will give researchers an entirely new platform for studying genetic and environmental influences over time on a wide variety of health conditions, across diverse populations.

The program is being funded by a $24.8 million grant from the National Institutes of Health (NIH)1, and over the next two years, a significant portion of this amount is expected to be used to purchase the Axiom Genotyping Solution.

The Kaiser Permanente RPGEH is a growing resource for scientific research designed to facilitate epidemiologic studies of both genetic and environmental influences on common health conditions, such as heart disease, diabetes, cancer, asthma, mental health disorders, and many others.

“The NIH grant gives Kaiser Permanente and UCSF an opportunity to utilize a new model for studying human genetics,” said Kevin King, president and CEO of Affymetrix. “We greatly value the relationship we have built with the program leaders over the last two years, and we are excited that our technology will be used to help researchers study effective prevention and treatment strategies to improve healthcare and quality of life.”

The Axiom Solution is configured to continually validate and incorporate the output of large-scale sequencing projects. Initial offerings are designed from public databases of human variations and cover historical HapMap data supplemented by subsequent releases of additional variants. In addition, Affymetrix is screening millions of putative SNPs and insertions/deletions that are being discovered by the 1000 Genomes Project and other sources, and will make these available to researchers using the Axiom Solution.

The solution consists of Axiom Array Plates, complete Axiom Reagent Kits, an automated target preparation station developed jointly by Affymetrix and Beckman Coulter, plus the GeneTitan™ Multi-Channel (MC) Instrument. The GeneTitan MC Instrument integrates a hybridization oven, fluidics processing, CCD imaging device, and analysis software for maximum data reproducibility, user productivity, and scalability.

For more information on the Axiom Genotyping Solution, please visit www.axiom.affymetrix.com.

1Kaiser Permanente and UCSF joint press release:

https://xnet.kp.org/newscenter/pressreleases/ncal/2009/101209rpgehanducsfgrant.html

About Affymetrix

Affymetrix technology is used by the world’s top pharmaceutical, diagnostic, and biotechnology companies, as well as leading academic, government, and not-for-profit research institutes. More than 1,800 systems have been shipped around the world and more than 20,000 peer-reviewed papers have been published using the technology.

Affymetrix is headquartered in Santa Clara, Calif., and has manufacturing facilities in Cleveland, Ohio, and Singapore. The company has about 1,100 employees worldwide and maintains sales and distribution operations across Europe and Asia. For more information about Affymetrix, please visit the company’s website at www.affymetrix.com.

Forward-looking Statements

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. These and other risk factors are discussed in Affymetrix’ Form 10-K for the year ended December 31, 2008, and other SEC reports for subsequent quarterly periods.

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