Affymetrix, Inc. (NASDAQ:AFFX) today announced that based on preliminary financial data, the Company expects to generate positive operating income and net income on a GAAP basis for the fourth-quarter of 2010. Total revenue for the fourth quarter is expected to be approximately $85 million and includes a $4.8 million milestone payment from a “Powered by Affymetrix” diagnostic partner.

The Company also announced that it has repurchased an additional $53 million face value of 3.5% convertible notes. The Company repurchased more than $150 million of 3.5% convertible notes in 2010 and now has about $95 million in outstanding convertible debt. The Company expects to have a year-end net cash balance of approximately $140 million.

“We made significant progress in 2010 and we expect to report positive operating income and net income for both the fourth quarter and the second half of 2010,” said Kevin M. King, president and chief executive officer. “These results reflect our disciplined focus on operations which has significantly lowered our break-even point. We exit 2010 in a strong financial position and we are committed to the continued improvement of our business in 2011 and beyond.”

Affymetrix will webcast its presentation at the 29th Annual JP Morgan Healthcare Conference on Thursday, January 13, 2011 at 7:30 a.m. PT. A live webcast will be available at https://www.affymetrix.com under the “Investors” link. The archived webcast will be available for 30 days.

Affymetrix’ management team will host a conference call on February 2, 2011 at 2:00 p.m. PT to review its operating results for the fourth quarter and fiscal year 2010. A live webcast can be accessed by visiting the Investor Relations section of the Company’s website at www.affymetrix.com. In addition, investors and other interested parties can listen by dialing domestic: (877) 407-8291, international: (201) 689-8345.

A replay of this call will be available from 5:00 p.m. PT on February 2, until 8:00 p.m. PT on February 9, 2011 at the following numbers: domestic: (877) 660-6853, international: (201) 612-7415. The passcode for both replays is 364850. An archived webcast of the conference call will be available under the Investor Relations section of the Company’s website.

About Affymetrix

Affymetrix technology is used by the world’s top pharmaceutical, diagnostic, and biotechnology companies, as well as leading academic, government, and nonprofit research institutes. More than 2,000 systems have been shipped around the world and more than 22,000 peer-reviewed papers have been published using the technology.

Affymetrix is headquartered in Santa Clara, Calif., and has manufacturing facilities in Santa Clara, Cleveland, Ohio, and Singapore. The company has about 1,000 employees worldwide and maintains sales and distribution operations across Europe and Asia. For more information about Affymetrix, please visit www.affymetrix.com.

Forward-looking statements

Affymetrix has not filed its Annual Report Form 10-K for the year ended December 31, 2010. All financial results described in this press release should be considered preliminary and unaudited, and are subject to change to reflect any necessary corrections or adjustments, or changes in accounting estimates, that are identified prior to the time the Company files its Annual Report on Form 10-K for the year ended December 31, 2010.