GENOME ANALYSIS WITH GENE-EXPRESSION MICROARRAYS

Advances in biochemistry, chemistry and engineering have enabled the d evelopment of a new gene expression assay. This 'chip-based' approach utilizes microscopic arrays of cDNAs printed on glass as high-density hybridization targets. Fluorescent probe mixtures derived from total c ellular messenger RNA (mRNA) hybridize to cognate elements on the arra y, allowing accurate measurement of the expression of the correspondin g genes. Array densities of >1,000 cDNAs per cm(2) enable quantitative expression monitoring of a large number of genes in a single hybridiz ation. A two-color fluorescence detection scheme allows rapid and simu ltaneous differential expression analysis of independent biological sa mples. Mass-produced microarrays provide a new tool for genome express ion analysis that may revolutionize genetic dissection, drug discovery and human disease diagnostics.