AFFX Affymetrix, Inc.

Affymetrix Inc. (Nasdaq:AFFX) announced today that it has granted Tessarae Inc. non-exclusive access to its microarray technology to develop and market epidemiological research tests for public health and biodefense surveillance. As part of the Powered by Affymetrix� program, the TessArray� kits simultaneously detect and identify hundreds of strains of natural and emergent viral and bacterial pathogens, as well as biothreat agents. The resulting information will enable researchers to better understand and respond to pandemic infectious disease threats. Traditional microbial detection and identification methods are based on phenotypic traits, such as the organism�s ability to grow on certain carbon sources or catalyze the conversion of specific substrates. The TessArray kits are based on multiplexed genotypic signatures present on the Affymetrix CustomSeq� Resequencing Arrays. These arrays have been designed and fabricated to detect a set of upper respiratory pathogen-specific target sequences provided by the United States Naval Research Laboratory. Public health officials can use the resulting information to quickly identify the most likely agent strain(s) associated with disease outbreaks. �The new Affymetrix microarray-based TessArray kits represent common viral and bacterial pathogens associated with acute respiratory disease and pneumonia, as well as biothreat agents that can elicit similar respiratory symptoms,� said Clark Tibbetts, Ph.D., co-founder and chief technology officer at Tessarae. �For example, the TessArray� RPM-Flu Kit detects and distinguishes avian H5N1 from other influenza strains and respiratory pathogens, and simultaneously identifies any known or previously unknown mutations that may elevate strain virulence and pandemic risk. A single-specimen, single-test, same-day result is a significant breakthrough for real-time global epidemiology.� Tessarae President and Co-Founder Klaus Schafer, M.D., M.P.H., adds, �Investigators at collection sites can determine whether detected pathogen strains warrant elevated epidemic or pandemic concerns. The TessArray kits enable a level of strain and sub-strain discrimination not possible with other array-based methodologies, as well as the ability to detect and characterize novel nucleotide changes in the pathogen genome sequence at the same time.� �With the recent emergence of new infectious diseases such as avian influenza, it is important for global health organizations to have access to comprehensive epidemiological surveillance research tools,� said Robert Lipshutz, Ph.D., senior vice president, Corporate Development and Emerging Markets at Affymetrix. �We are pleased to have Tessarae join our Powered by Affymetrix program and we anticipate that the availability of these types of microarray-based testing kits and services will allow epidemiologists to better monitor the spread of pathogens and detect mutations that may alter their potential to cause a pandemic.� The Powered by Affymetrix program enables commercial entities to license GeneChip� technology to develop microarray products for applications in diagnostics, forensics, animal testing, industrial testing, food testing and more. About Tessarae Tessarae was founded in 2005 to develop and provide advanced genomic microarray applications, products and services as support tools for critical decision makers. Leveraging the molecular genomics, infectious disease, medicine and public health experience of its founders, Tessarae offers a turnkey solution for simultaneous detection and identification of known and unknown strains and variants of pathogenic agents. The TessArray� RPM-Flu3.0 array represents four years and over $35 million of R&D expenditures of the U.S. Department of Defense to develop and validate the platform for public health and biodefense screening and surveillance of respiratory disease agents. Validation exercises in real-world epidemic outbreak venues demonstrated superior sensitivity and specificity of the TessArray� RPM platform, compared with gold-standard benchmarks of microbial culture and/or molecular tests using polymerase chain reaction (PCR) methodologies. In November 2006, Tessarae was granted license to the U.S. government patent portfolio for commercialization of the platform and related applications worldwide. Complementary TessArray� RPM-based applications are now in development, including encephalitis, hemorrhagic fever, and other latent and acute blood-borne infections. For more information about Tessarae, please contact info@tessarae.com or for inquiries on Tessarae�s global surveillance project, contact pandemiology@tessarae.com. 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� 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., 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 agreement between Affymetrix and Tessarae discussed in this press release; risks of the company�s ability to achieve and sustain higher levels of revenue, higher gross margins and reduced operating expenses; uncertainties relating to technological approaches, manufacturing and 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. Tessarae, the Tessarae logo and TessArray� are trademarks in use by Tessarae Inc. and its affiliate Tessarae LLC.