Fluorescent In Situ Hybridization

Abstract

In situ hybridization (ISH) technique was introduced by Gall and Pardue¹ in 1969. At that time the technique was limited by the use of radioactively labelled probes that were subsequently visualized by autoradiography. The development of interphase cytogenetics in the 1980s and fluorescent labels in 1986² has seen the technology applied in a number of fields. Although fluorescent in situ hybridization (FISH) is a valuable research tool, it is now also a technique employed in the diagnostic laboratory. It is currently a standard tool in cytogenetics laboratories, where it is used for the diagnosis of hereditary disorders, chromosomal aberrations, and hematologic cancer markers. More recently, the technique has been applied to formalin-fixed, paraffin-embedded cells and tissues. The application of FISH to detect gene amplifications (HER2 in breast cancer),³ gene rearrangements (BCR-ABL in leukaemias),⁴ microdeletions,⁵ chromosomal duplication, and viral infections (HPV) highlights the importance of this methodology, not only in the clinical setting but in wider research applications.