What is the background of Fluorescent In Situ Hybridization?

Question

Fluorescence in situ hybridization (FISH), developed in 1980s, is a cytogenetic technique using fluorescent probes to bind the chromosome with a high degree of complementarity. It is a powerful and easy method to detect RNA or DNA sequences in cells, tissues and tumors. This technique is useful for identifying chromosomal abnormalities, gene mapping, characterizing somatic cell hybrids, checking amplified genes and studying the mechanism of rearrangements. RNA FISH is used to measure and localize mRNAs and other transcripts within tissue sections or whole mounts.