Davis Polk is advising Affymetrix, Inc. on its approximately $330 million acquisition of eBioscience Holding Company, Inc. The transaction, which is expected to close in the fourth quarter of 2011, is subject to customary regulatory approvals and closing conditions, including receipt by Affymetrix of the proceeds of the debt financing for the transaction.

Headquartered in Santa Clara, California, Affymetrix provides technology used by the world’s top pharmaceutical, diagnostic and biotechnology companies, as well as leading academic government and nonprofit research institutes. More than 2,100 Affymetrix systems have been shipped around the world and more than 25,000 peer-reviewed papers have been published using Affymetrix technology. Headquartered in San Diego, California, eBioscience provides innovative, high quality reagents to academic and government researchers and pharmaceutical and biotechnology companies worldwide that empower the process of scientific discovery in the areas of cellular immunity and oncology.

The Davis Polk corporate team includes partners William M. Kelly and Sarah K. Solum and associates Vincent T. Cannon and John Dalton. The tax team includes partner Rachel D. Kleinberg and associate Una Au. Partner Karin S. Day and associate Shakhi Majumdar are providing credit advice. Counsel Cynthia Akard is providing benefits advice. Counsel Stephen M. Pepper is providing antitrust advice. Counsel Loyti Cheng and associate Kevin J. Klesh are providing environmental advice. Members of the Davis Polk team are based in the Menlo Park and New York offices.

www.davispolk.com