Affymetrix Redefines Association Studies with Introduction of SNP 5.0 Array.

Company Releases Its Most Comprehensive Single Array for Genetic Studies

SANTA CLARA, Calif. -- Affymetrix Inc. (NASDAQ:AFFX) announced today that its new single-chip SNP 5.0 Array was made available as a limited release in December. The new array features single nucleotide polymorphisms (SNPs) from the original two-chip 500K Array Set, as well as 500,000 additional probes that can measure other genetic differences, such as copy number variation. The SNP 5.0 Array gives researchers a significant increase in information above the original 500K Array Set for the same price, while reducing the array processing time.

The Affymetrix SNP 5.0 Array was developed in collaboration with the Broad Institute of Harvard and the Massachusetts Institute of Technology to better identify and understand the genetic variations associated with complex diseases such as autism, autoimmunity, bipolar disease, cancer, diabetes and heart disease. Scientists from the Autism Consortium and the Broad Institute are using the SNP 5.0 Array to perform the most comprehensive study to date on the genetics of autism.

"To understand the causes of complex genetic diseases, our investigators want simultaneously to test both SNPs and copy number variants, all in the same experiment. The new Affymetrix SNP 5.0 Array makes this possible, integrating what had previously required two separate technologies," said David Altshuler, M.D., Ph.D., director of the Program in Medical and Population Genetics at Broad. "The SNP 5.0 Array not only draws on the most current data from the International HapMap Project to guide SNP assay design, but also from the rapidly emerging database of common copy number variants to direct placement of additional probes."

"The Affymetrix SNP 5.0 Array is a perfect example of how the power of GeneChip([R])technology is helping to drive discovery," said Richard Rava, Ph.D., senior vice president, Research and Development at Affymetrix. "The SNP 5.0 Array is enabling scientists to see more information and increase the genetic power of their experiments to get results faster."

The SNP 5.0 Array will be commercially available by the end of the first quarter of 2007. Affymetrix is working with scientists from the Broad Institute to develop additional software tools for data analysis for the SNP 5.0 Array, as well as add additional SNPs to the next-generation SNP 6.0 Array that is scheduled to launch later this year.

The SNP 5.0 Array is the most recent addition to Affymetrix' line of genotyping products, including the 10K, 100K and 500K Arrays, which are all based on the proven Whole-Genome Sampling Assay. This technology is being used by more than 200 laboratories and has generated data for more than 150 peer-reviewed scientific publications.

For more information on recent discoveries using Affymetrix genotyping products, please visit:

Researchers Uncover Key Pathways Behind ALS: http://www.microarraybulletin.com/community/article.php?p=286

Researchers Discover Gene Contributing to Human Memory Performance: http://www.microarraybulletin.com/community/article.php?p=263

Researchers Discover Genetic Variant Associated with Obesity in Humans: http://microarraybulletin.com/community/article.php?p=133

Researchers Discover a New Susceptibility Gene for Juvenile Diabetes: http://www.microarraybulletin.com/community/article.php?p=203

About Affymetrix

Affymetrix scientists invented the world's first high-density microarray in 1989 and began selling the first commercial microarray in 1994. Since then, Affymetrix GeneChip([R])technology has become the industry standard in molecular biology research. 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 1,400 systems have been installed around the world and more than 7,000 peer-reviewed papers have been published using the technology. Affymetrix' patented photolithographic manufacturing process provides the most information capacity available today on an array, enabling researchers to use a whole-genome approach to analyzing the relationship between genetics and health. Affymetrix is headquartered in Santa Clara, Calif., with manufacturing facilities in Sacramento, Calif., and Bedford, Mass., and Singapore. The company maintains important sales and marketing operations in Europe and Asia, and has about 1,100 employees worldwide. For more information about Affymetrix, please visit the company's website 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 and uncertainties associated with the success of the SNP 5.0 Array discussed in this press release; 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; 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/A for the year ended December 31, 2005, 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 are registered trademarks owned or used by Affymetrix Inc.