[Contribution of in situ hybridization to chromosomal analysis]

In situ hybridization (ISH) is a new technique which allows localizing on chromosomes a molecule of DNA homologous to a given sequence of nucleic acids. It permits to improve the chromosomal analysis by marking any sequence of nucleic acids in interphase or metaphase. It opens new prospects for chromosomes mapping, study of evolution, chromosomal diagnosis, the role of oncogenes and chromosomal mechanics.