In Situ Hybridization: Basic Approaches and Recent Development

AbstractAbstractIn situ hybridization (ISH) allows for the histological and cytological localization of DNA and RNA targets. ISH has been useful as a research tool, and recent studies have used this technique in the diagnostic pathology laboratory and in microbiology for the tissue localization of infectious agents.However, the application of ISH techniques can be limited by their inability to detect targets with low copies of DNA and RNA. During the last few years, several strategies have been developed to improve the sensitivity of ISH by amplification of either target nucleic acid. sequences before ISH or signal detection after the hybridization is completed. Current approaches involving target amplification as in situ PCR, and signal amplification as tyramide deposition are reviewed with emphasis on their applications to bright field microscopy. Application of some of these techniques has extended the utility of ISH in diagnostic pathology and in research, because of the ability to detect targets with low copy numbers of DNA and/or RNA. (The J Histotechnol 27:000, 2004)Submitted: January 20, 2004; Accepted: January 22, 2004Keywords: in situ hybridizationsignal amplificationmolecular pathology