In Situ Hybridization (ISH)

A potent molecular method for locating and detecting particular DNA or RNA sequences inside cells or tissue slices is called in situ hybridization (ISH). A labeled nucleic acid probe is applied to a fixed biological sample, where it hybridizes to its complementary target sequence. Colorimetric reactions (CISH) or fluorescent signals (FISH) can be used for detection, depending on the labeling system. Researchers can see where and when particular genes are active in complex tissues or developmental stages thanks to ISH, which maintains the spatial context of gene expression.

Applications including gene expression profiling, chromosomal aberration detection, pathogen identification, and cancer diagnostics make extensive use of it in research, diagnostics, and pathology. When nucleic acid localization is just as crucial as its presence or abundance, ISH is especially useful because it provides high specificity, allowing for single-cell resolution.