User:Paphrag/sandbox
From Wikipedia, the free encyclopedia
A DNA microarray (also commonly known as gene or genome chip, DNA chip, or gene array) is a collection of microscopic DNA spots attached to a solid surface, such as glass, plastic or silicon chip forming an array for the purpose of gene expression profiling, genotyping, copy number analysis, loss of heterozygosity (LOH) analysis, or DNA-protein interaction (ChIP). The principal advantage of DNA microarrays over previous technologies, is that DNA microarrays allow the biological status of thousands of genes or genomic loci to be assayed simultaneously.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/0/0e/Microarray2.gif/640px-Microarray2.gif)
The affixed DNA segments are commonly known as probes (although some sources will use different nomenclature such as reporters), thousands of which can be placed in known locations on a single DNA microarray. Microarray technology evolved from Southern blotting, whereby fragmented DNA is attached to a substrate and then probed with a known gene or fragment. Using microarrays to assay genes or genomic loci is relevant to many areas of research biology and medicine, such as understanding cell biology, biochemical pathways, developmental stages of disease, and disease treatment. For example, microarrays can be used to identify genes involved in the progression of disease by comparing gene expression profiles of diseased cells to that of normal cells.