Fluorescence In Situ Hybridization (FISH) is a molecular cytogenetic technique that uses fluorescent probes to detect and localize specific DNA or RNA sequences within cells or tissues. It allows visualization of genetic abnormalities, gene expression, and chromosomal structure under a fluorescence microscope.

Key Features of FISH:

• High Specificity – Probes bind to complementary DNA/RNA sequences.

• Spatial Resolution – Preserves tissue/cell architecture while detecting genetic material.

• Applications – Used in cancer diagnostics (e.g., HER2 testing), prenatal testing (aneuploidy detection), microbial identification, and research (chromosomal abnormalities).

• Types – Includes DNA FISH, RNA FISH (for gene expression), and chromosome painting.

FISH is a powerful tool in genetics, pathology, and research, providing precise genomic information at the cellular level.