DNA microarray: Difference between revisions

Revision as of 03:40, 26 March 2004

Revision as of 03:41, 26 March 2004

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A '''DNA microarray''' (also '''DNA chip''' or ''gene chip'' in common speech) is a piece of [[glass]] or [[plastic]] on which single-stranded pieces of [[DNA]] have been affixed in a microscopic [[array]].

Machines use such chips to screen a biological sample for the presence of many [[genetic sequence]]s at once. The affixed DNA segments are known as '''probes.''' Hundreds of identical probes are affixed at each point in the array to make the chips effective detectors.

Although the name "GeneChip" is a trademark, microarray users generally use this term to refer to any microarray, not just those sold from a company. While Affymetrix arrays are limited to featuring small oligonucleotides of less than 25 bases, many microarrays consist of PCR products, genomic DNA, BACS, plasmids, or long oligos (70 bases). Microarrays may be made by any number of technologies, including simple printing onto glass slides. Microarrays for expression profiling was first published in 1995 (Science) and the first complete eukaryotic genome (Saccharomyces cerevisiae) on a microarray was published in 1997 (Science).