FISH
Also written as: FISH — Fluorescence In Situ Hybridization
A molecular technique using fluorescent probes to detect specific DNA sequences or chromosomal abnormalities in cancer cells.
Full Definition
Fluorescence In Situ Hybridization (FISH) is a molecular cytogenetic technique that uses fluorescently labeled DNA probes to identify specific genetic sequences within cells or tissues. In cancer diagnosis, FISH is commonly employed to detect gene amplifications, deletions, or translocations that have diagnostic, prognostic, or therapeutic implications. Examples include HER2 amplification in breast cancer, ALK rearrangements in lung cancer, and MYC translocations in lymphomas. Results are typically reported as ratios or percentages of positive cells.
Usage
Usage note: Always specify the gene or chromosomal region being tested (e.g., HER2 FISH, ALK FISH).
In Context
- "FISH analysis confirmed HER2 amplification with a ratio of 3.2, indicating eligibility for trastuzumab therapy." — Molecular pathology report
- "ALK rearrangement was detected by FISH in 15% of tumor nuclei, supporting treatment with crizotinib." — Genetic testing report