The Centers for Disease Control and Prevention intends to issue a sole source purchase order to Affymetrix, Inc, 3420 Central Expressway, Santa Clara, CA 95051, for GeneChip Human Ex0n 1.0 ST array 30-array pack and WT Target labeling and control reagents in 30-reaction kit to continue gene expression analysis of participants in the Trier Social Stress Test component of a Chronic Fatigue Syndrome study at Emory University. These arrays and reagents are to be used in existing Affymetrix equipment, which allows CDC to examine the gene expression profiles of all 30,000 known genes, as well as alternative splicing and different promoter usage of genes, and will complete analysis begun in 2008. CDC believes that this requirement is met by only one provider. This procurement will be processed under the authority of FAR 6.302-1 and 6.302-2. Only one responsible source and no other sources will satisfy agency requirements. No solicitation is being issued. Interested persons may identify their interest and capability to respond to this requirement. This procurement is not set-aside for small business. For contractual questions contact Linda M. Young.