Comparison between different strategies of covalent attachment of DNA to glass surfaces to build DNA microarrays

DNA microarray is a powerful tool allowing simultaneous detection of many d ifferent target molecules present in a sample. The efficiency of the array depends mainly on the sequence of the capture probes and the way they are a ttached to the support. The coupling procedure must be quick, covalent, and reproducible in order to be compatible with automatic spotting devices dis pensing tiny drops of liquids on the surface. We compared several coupling strategies currently used to covalently graft DNA onto a glass surface. The results indicate that fixation of aminated DNA to an aldehyde-modified sur face is a choice method to build DNA microarrays. Both the coupling procedu re and the hybridization efficiency have been optimized. The detection limi t of human cytomegalovirus target DNA amplicons on such DNA microarrays has been estimated to be 0.01 nM by fluorescent detection. (C) 2000 Academic P ress.