Fluorescence in-Situ Hybridization (FISH) and its Importance in Bio-Medical Sciences

Abstract

FISH is a technique that measures gene amplification using fluorescently labeled DNA (probe). The sample of breast tumor tissue is prepared for FISH by heating it. This heating process breaks the DNA into two strands; this produces two single strands of DNA and is called denaturing. The labeled probe is added to the denatured DNA mixture. The fluorescently labeled DNA matches certain regions of the denatured DNA and when the matching regions come in contact with each other they stick together. The mixture is washed so any unbound labeled DNA is removed. The washed mixture is viewed using a special microscope that can detect the color emitted by the probe. The probe marks the areas of DNA (genes) that code for the protein of interest, thus the amount of probe bound to the DNA is an indirect indicator of the number of genes present coding for the protein.