An introduction to arrays.

DNA microarrays are a new technology that allows the analysis of large numbers of genes at a high resolution by the hybridization of labelled DNA, which may be reverse-transcribed from mRNA, to a substrate containing thousands of spotted cDNAs or oligonucleotides. The amount of hybridized target is analysed, giving information on gene expression, polymorphisms or mutations present and allowing the gene profiling of different subtypes of disease. This technique has massive implications for the further understanding of the complicated genetic alterations involved in tumourigenesis and other disease processes and also for the generation of accurate prognostic information and optimization of treatment in these situations. Copyright 2001 John Wiley & Sons, Ltd.