SANTA CLARA, Calif., Jan. 8, 2007 — Affymetrix, Inc. has announced that the latest version of Affymetrix Copy Number Analysis Tool (CNAT) software is now available for download on the Affymetrix website. CNAT 4.0, which will support Affymetrix 500K Mapping Arrays, incorporates a new algorithm developed to identify chromosomal gains and losses and loss of heterozygosity (LOH) using high-density oligonucleotide arrays and the whole-genome sampling assay (WGSA).

“To develop CNAT 4.0, we took the same, proven data analysis capabilities of CNAT 3.0

and expanded them to include Affymetrix 500K Mapping Arrays,” said Jody Courtney, product manager at Affymetrix. “And by implementing new, state-of-the-art algorithms, CNAT 4.0 improves data quality across all Affymetrix Mapping Arrays.” CNAT 4.0 includes a new Hidden Markov Model (HMM) algorithm for copy number and LOH in addition to new data normalization algorithms.

Upgrades also include an enhanced viewer that allows whole-genome, chromosome-specific as well as multi-sample views to facilitate the identification of trends in copy number and loss-of-heterozygosity data.

In addition to direct export to Affymetrix’ Integrated Genome Browser (IGB), CNAT 4.0 enables users to export data to upload directly into the University of California, Santa Cruz Browser.

Similar to previous versions, CNAT 4.0 is integrated into the Affymetrix GeneChip® Genotyping Analysis Software (GTYPE). CNAT 4.0 can be downloaded directly from the Affymetrix website with minimal registration.