In situ hybridization probes - Molecular cytogenetics

Molecular cytogenetics is a new morphological approach that uses the tools of both molecular biology and cytogenetics. Molecular cytogenetics was created to provide additional information to classical cytogenetics. This tool has made it possible to cover part of a field of study that had not previously been exploited. The main technique used in molecular cytogenetics is fluorescence in situ hybridization (FISH). The principle is based on the use of a molecular probe, i.e. a small sequence of DNA (or RNA) whose normal location is known in the genome and which is chemically labelled so that it can be subsequently located. The resolving power of FISH (less than 1Kb) allows a fine analysis of the structure of the chromosomes. FISH is used in all areas of classical cytogenetics. This includes post- and prenatal diagnosis as well as pre-implantation diagnosis. FISH allows microdeletion research or pantelomeric studies.