Fluorescence In-Situ Hybridization
Fluorescence in-situ Hybridization (FISH) is a branch of cancer genetics that focuses on detecting and locating the presence or absence of specific DNA sequences on chromosomes. FISH is also referred to as Molecular Cytogenetics.
To perform FISH, cells are fixed onto the surface of a slide, and then the slide is treated so that the chromosomal DNA is denatured into single strands.
Then, special fluorescently labeled DNA probes are applied onto the slide. The DNA probes are small pieces of single stranded DNA with a sequence from the gene of interest. Probes are only able to hybridize with their complimentary sequence, which is the gene or locus of interest on a particular chromosome. The DNA probes are allowed to hybridize with the denatured chromosomal DNA, and any excess probes are washed away.
After the excess probes are washed away, the slide is then viewed under a fluorescence microscope. The fluorescently labeled molecules reveal the physical location of the gene or locus of interest. Pathologists will then use specified cut off values to assess the results of the FISH test.
Frequently Ordered Test(s):
View our full list of Probes and available Panels here.