Fluorescence In Situ Hybridization (FISH) and Its Applications

Fluorescence in situ hybridization (FISH) is the most convincing technique for locating the specific DNA sequences, diagnosis of genetic diseases, gene mapping, and identification of novel oncogenes or genetic aberrations contributing to various types of cancers. FISH involves annealing of DNA or RNA probes attached to a fluorescent reporter molecule with specific target sequence of sample DNA, which can be followed under fluorescence microscopy. The technique has lately been expanded to enable screening of the whole genome simultaneously through multicolor whole chromosome probe techniques such as multiplex FISH or spectral karyotyping or through an array-based method using comparative genomic hybridization. FISH has completely revolutionized the field of cytogenetics and has now been recognized as a reliable diagnostic and discovery tool in the fight against genetic diseases.