DNA microarrays, as the name suggests, are arrays of oligonucleotides, cDNAs, or other DNA targets, which promise to advance several biomedical goals. First, microarrays allow researchers to track global gene expression patterns characteristic of normal and disease states, and to identify genes that are up- or down-regulated when a drug or signaling factor is added.1 Such information can advance drug discovery efforts. Second, since gene expression patterns vary between physiological states or in different regions of an organ, such as the brain, there is considerable interest in the generation of comparative three-dimensional maps of gene expression in normal and diseased tissues.4 These maps can be produced by combining laser capture microdissection (LCM),5 single-cell DNA amplification, and microarray analysis. Finally, arrays can aid single-nucleotide polymorphism (SNP)3 and mutation pattern mapping, thus potentially individualizing medical treatments.
Scientists can label samples for microarray analysis with either radionuclides or fluorophores. Direct or indirect fluorescence ...
