What is Affymetrix GeneChip array?
The Affymetrix GeneChip system provides an approach to comparatively analyze genome wide patterns of gene expression using a technology that incorporates miniaturized, high density arrays of 25mer oligonucleotide probes. The probe arrays are manufactured by Affymetrix’s proprietary, light directed chemical synthesis process, which generates high density arrays of oligonucleotides that possess a predefined position on the array. These arrays are used to monitor gene expression for thousand of transcripts. A transcript is represented as a probe set. A probe set is made up of probe pairs comprised of a perfect match (PM) and a mismatch (MM) probe cells. This probe pairing strategy identifies and minimizes the effects of non specific hybridization and background signal. The intensities of each probe pair are used to determine the expression measurement. This measurement is calculated for each probe set and is described in the form of qualitative and quantitative values using the Microarray
