FISH assay
Also written as: FISH — Fluorescence In Situ Hybridization
Fluorescence in situ hybridization test used to detect chromosomal aberrations and gene amplifications in tumor samples.
Full Definition
FISH (fluorescence in situ hybridization) assay is a cytogenetic technique that uses fluorescent DNA probes to identify specific chromosomal abnormalities within tumor cells. This diagnostic tool is essential for detecting gene amplifications, deletions, and translocations that inform targeted therapy selection. FISH results provide quantitative measurements of gene copy numbers and are particularly important for HER2 testing in breast cancer and ALK rearrangements in lung cancer. The assay requires specialized laboratory equipment and trained cytogeneticists for accurate interpretation.
Usage
Usage note: Always capitalize FISH; use 'assay' not 'test' in formal clinical documentation.
In Context
- "FISH assay confirmed HER2 amplification with a ratio of 3.2." — Pathology report
- "The laboratory performed FISH assay to evaluate ALK gene rearrangement status." — Molecular diagnostics report