SANTA CLARA, Calif..–Affymetrix Inc. (Nasdaq:AFFX) today announced the completion of its acquisition of privately held ParAllele BioScience, Inc., a provider of highly-scalable technology for comprehensive genetic studies. In connection with the completion of the acquisition, ParAllele stockholders will receive approximately $120.8 million in the form of approximately 2.29 million shares of Affymetrix common stock and $11.7 million in cash in exchange for all of their outstanding shares and the assumption of all of ParAllele’s stock options. The acquisition was approved by ParAllele stockholders on October 20, 2005 and was completed on October 21, 2005.

“The acquisition of ParAllele will significantly accelerate the delivery of next-generation products to the marketplace,” said Stephen P.A. Fodor, Ph.D., Founder, Chairman and Chief Executive Officer of Affymetrix. “ParAllele and Affymetrix’ innovative technologies will be combined to deliver new discovery products for basic research and a scalable platform for the delivery of healthcare diagnostics.”

The companies are already offering new genotyping products based on the ParAllele technology and will continue to leverage these capabilities to develop products for the expanding genetic studies market. With the completion of this transaction, Affymetrix is increasing its portfolio of products to include new 1,500 SNP custom assays and 20,000 non-synonymous coding SNP assays.

ParAllele was founded in October 2001 by a team of scientists from the Stanford Genome Technology Center. The founding team consisted of physicists, geneticists and technologists driven by a common desire to use cutting-edge technology to solve real-world problems in genetics. ParAllele has approximately 75 employees who will be joining Affymetrix.