An introduction to DNA chips

The GeneChip, which is gaining popularity throughout the field of molecular biology and biotechnology, is a recently developed technique which provides efficient access to genetic information using miniaturized, high-density arrays of DNA or oligonucleotide probes. Both fundamental and applied research benefit greatly from the specific advantages of this method. Initially developed to enhance genome sequencing projects, the technology is rapidly evolving and has been adapted to a large set of applications. DNA chips are powerful tools to study the molecular basis of interactions on a scale that would be impossible using conventional analysis. The recent development of the microarray technology has greatly accelerated the investigation of gene regulation. Arrays are mostly used to identify which genes are turned on or off in a cell or tissue, and also to evaluate the extent of a gene’s expression under various conditions. Indeed, this technology has been successfully applied to investigate simultaneous expression of many thousands of genes and to the detection of mutations or polymorphisms, as well as for their mapping and sequencing. In this chapter, we discuss the format of DNA chips, the technology used to fabricate and read them, and their applications