Affymetrix Technology and Instrumentation

Affymetrix GeneChips® are available for numerous organisms including human, mouse, rat, yeast, Drosophila melanogaster, Caenorhabditis elegans, and Arabidopsis thaliana. Custom arrays are also available from Affymetrix. The microarrays consist of 25-mer oligonucleotides that are synthesized in situ by photolithography onto silicon wafers. GeneChips™ contain up to a million unique oligonucleotide features, covering more than 39,000 transcript variants. Each gene is represented by at least one set of 11 different "probe pairs". A probe pair consists of a 25-base-pair (bp) "perfect-match" (PM) oligonucleotide probe and a 25-bp "mismatch" (MM) probe, in which the 13th position is designed not to match the target (cellular) sequence. The information across all 11 paired PM and MM probes (the "probe set") is integrated by proprietary Affymetrix Microarray Suite (MAS) software to calculate the signal.

In contrast to cDNA microarrays, each mRNA preparation is hybridized to a separate oligonucleotide array. Hybridization, washing, and staining of Affymetrix GeneChips™ takes place in a highly standardized setup, which greatly reduces the variability of microarray processing. Please refer to http://www.affymetrix.com/technology/design/index.affx for a detailed description of Affymetrix GeneChip® microarrays.

The Bauer Core has a complete GeneChip® Instrument System, which is a fully integrated platform for conducting research using GeneChip® probe arrays. This system includes the GeneChip® Scanner 3000, two Fluidics Station (one model 400 and one model 450), two Hybridization Oven 640s, and a computer workstation loaded with Affymetrix GeneChip® Operating Software (GCOS) Version 1.0. Each Fluidics Station can process up to four GeneChips® at one time. The Scanner 2500 processes one GeneChip® at one time. Fluidics protocols and scanning times vary depending on the chip format.

The Bauer Core offers competitive academic pricing for GeneChip® microarrays. Please visit the Affymetrix website at www.affymetrix.com for information about their most current GeneChips®.