The genome on a chip has arrived. With pieces of all 30,000 or so known human genes, the new integrated gene chips, or microarrays, will allow scientists to scan all genes in a human tissue sample at once to determine which genes are active (turned on) in an organ compared with those active in a healthy organ. Pharmaceutical companies will use them to predict drug effects.

This previously required two or more chips. The new whole-genome chips will lower the cost and increase the speed of testing to achieve the genomics equivalent of Moore’s law.