AFFX Affymetrix, Inc.

Affymetrix, Inc. (Nasdaq:AFFX) today announced that its technology was used by the Cincinnati Children�s Hospital Medical Center to develop an innovative molecular diagnostic test designed to help diagnose the genetic defects in patients with inheritable forms of jaundice. Jaundice is the most common symptom of liver disease in young children. Cincinnati Children�s has made the CLIA- and CAP-approved laboratory developed test available to clinicians around the world. Research shows jaundice occurs in one out of every 2,200 live births in the U.S.1 Although many cases resolve spontaneously, patients with pathologic jaundice (also known as cholestasis) may progress to end-stage liver disease or cirrhosis. Until now, evaluation has frequently determined the extent of liver injury in patients with jaundice. Cincinnati Children�s intends the Jaundice Chip to enable diagnoses to be expanded to include genetic causes and more precisely identify patients at high risk for progressive liver disease. A team of scientists led by Jorge Bezerra, M.D., professor of pediatrics and director of gastroenterology research at Cincinnati Children�s, designed the Jaundice Chip, a custom microarray. In a study published in the January 2007 issue of the Journal of Gastroenterology, Dr Bezerra reported the Jaundice Chip is highly effective in detecting the five most common genetic mutations in children with inherited causes of jaundice. Those five diseases represent about half of all pediatric chronic liver disease cases.2 �We are proud of the team at Cincinnati Children�s for creating a custom array that enables researchers to draw clearer conclusions as to the causes of jaundice,� said Kevin King, president of Affymetrix. �This test is further proof of Affymetrix enabling scientists to innovate and use our products to meet the unmet needs of the market.� Affymetrix offers a continuous path to discover, develop, and commercialize complex biomarker signature assays. The GeneChip� System 3000Dx is the only microarray instrumentation platform to receive regulatory clearance by the U.S. FDA and to be CE marked in the European Union for in vitro diagnostic use. The CLIA-certified Affymetrix Clinical Services Laboratory (ACSL) offers microarray-based molecular diagnostic patient and clinical trial testing services which enable customers to leverage Affymetrix' technology and experience to bring more effective molecular diagnostic tests to patients faster than ever before. 1 Arya G. et al., Pediatric liver disease in the United States: epidemiology and impact, J. Gastroenterol. Hepatol, 17(5): 521-5, (May 2002) 2 Liu C. et al., Novel resequencing chip customized to diagnose mutations in patients with inherited syndromes of intrahepatic cholestasis, J. Gastroenterol. Hepatol, 132(1):119-26. (Jan 2007) For more information on the Jaundice Chip developed on the Affymetrix platform, visit Cincinnati Children�s at: http://www.cincinnatichildrens.org/health/subscribe/ped-insights/05-07/jaundice-chip.htm About Affymetrix Affymetrix GeneChip� microarray technology is the industry-standard tool for analyzing complex genetic information. After inventing microarray technology in the late 1980s, Affymetrix scientists have been dedicated to developing innovative products that provide researchers with a more complete view of the genome. These products continue to accelerate genetic research and enable scientists to develop diagnostics and tailor treatments for individual patients by identifying and measuring the genetic information associated with complex diseases. Today, 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 14,000 peer-reviewed papers have been published using the technology. Affymetrix is headquartered in Santa Clara, Calif., and has manufacturing facilities in Sacramento, Calif., 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, including, but not limited to: risks and uncertainties relating to commercial success of the agreement with Cincinnati Children�s 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 related to technological approaches, manufacturing and product development; personnel retention; uncertainties related to cost and pricing of Affymetrix products; dependence on collaborative partners; uncertainties related to sole-source suppliers; risks associated with past and future acquisitions; 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, 2007, 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.