In situ hybridization of fluorescent probes on chromosomes, nuclei or stretched DNA: applications in physical mapping and characterization of genomic rearrangements.

During the last few years, various technologies and applications of fluorescence in situ hybridization (FISH) have been developed. Hybridization on nuclei allows an increase in the resolution of the technique. It also permits the characterization of some chromosomal abnormalities such as trisomies, monosomies or translocations in pathological cells when it is difficult to obtain metaphases. Recently, several methods which extend the chromatin or the DNA molecules have been developed. Such a support increases the FISH resolution to the molecular level.