Fluorescent in situ hybridization was initially developed in the late 1980's from radioactive hybridization procedures used for mapping human genes. Eventually, this technology was utilized for the for the characterization of chromosomal rearrangements and marker chromosomes, the detection of microdeletions, and the pre-natal diagnosis of common aneuploidies in clinical cytogenetics laboratories. Today, numerous DNA probes have been commercialized, further promoting the wide-spread clinical applications of molecular cytogenetics.
With current FISH techniques, deletion or rearrangement of a single gene can be detected, cryptic chromosome translocations can be visualized, the copy number of oncogenes amplified in tumor cells can be assessed, and very complex rearrangements can be fully characterized.
Using interphase FISH, genomic alterations can be studied in virtually all types of human tissues at any stage of cell division without the need of cell culture and chromosome preparation.