Affymetrix Launches GeneChip® AutoLoader for the GeneChip® Scanner 3000 System - New 48-array GeneChip^® AutoLoader gives researchers walk-away freedom

Santa Clara, Calif., Sept. 23, 2003 – Affymetrix, Inc., (NASDAQ: AFFX) today launched its new GeneChip^® brand AutoLoader for the GeneChip^® Scanner 3000, a 48-array carousel that automatically loads and unloads arrays, helping researchers automate their array processing and providing walk-away freedom in the lab.

The GeneChip AutoLoader can scan 48 current catalog arrays in 4.5 hours or less, depending on the array format of the experiments run. The AutoLoader attaches to the top of the scanner, saving valuable bench space, and does not require any additional power source. 

The GeneChip AutoLoader is part of the recently introduced GeneChip Scanner 3000 system, a fourth-generation, integrated genetic analysis system that supports smaller feature sizes, higher resolution and greater information content in Affymetrix microarray-based products.

 “Affymetrix is the industry pioneer that invented the DNA microarray and microarray scanner and the GeneChip AutoLoader is another innovation that will save researchers  time and effort by enabling automatic operation of the GeneChip Scanner 3000,” said Tony McCook, Affymetrix’ Senior Product Manager, Instrumentation. “Ease-of-use features like the temperature-controlled carousel with batch or load-on-demand options, give researchers walk-away freedom and increase their efficiency and flexibility in the lab.”

Features on the new GeneChip AutoLoader include:

• The AutoLoader is the only scanner that provides a temperature-controlled environment to maintain long-term sample stability and integrity.
• The AutoLoader provides e-mail notification to designated users in the event of a system failure.
• The AutoLoader offers flexible array scanning options. Operators can scan arrays unattended in a completely automatic mode, individually in a manual mode or even add arrays to a batch that is already in progress.

More information on the GeneChip AutoLoader and other Affymetrix instruments may be found on the Affymetrix website—www.affymetrix.com.

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 AutoLoader), 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)20 7886 8152, s.charles@northbankcommunications.com

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