Oligonucleotide Microarray Analysis of Gene Expression in Leukemia

Analysis of gene expression is used to appreciate gene function, as the pool of messenger RNA (mRNA) determines, at least partly, the physiological status of the cell. Until now it has been possible to measure single gene function only by Northern assays or reverse transcriptase-polymerase chain reaction (RT-PCR). With the development of microarrays it is possible today to analyze global gene expression patterns in a quantitative fashion. This can be used to understand biological processes (1 ) and to identify new disease classes (2 -7 ) or drug targets (8 ). Other uses include genotyping (9 ), comparative genomic hybridization (10 ), and analysis of DNA-protein interaction (11 ). The amount of data produced by these experiments is formidable, and application of bioinformatics is integral to this technology.