FISH analysis
Also written as: FISH — fluorescence in situ hybridization
Fluorescence-based genetic testing technique used to detect specific chromosomal abnormalities in embryos or fetal cells.
Full Definition
Fluorescence in situ hybridization (FISH) analysis is a cytogenetic technique that uses fluorescent probes to detect specific DNA sequences or chromosomal regions. In reproductive genetics, FISH has been used for preimplantation genetic testing and prenatal diagnosis to identify common aneuploidies such as trisomy 21, 18, and 13, as well as sex chromosome abnormalities. While largely superseded by more comprehensive technologies like chromosomal microarray and next-generation sequencing, FISH remains valuable for detecting specific structural chromosomal rearrangements and confirming certain genetic diagnoses. Results are typically available within 24-48 hours.
Usage
Usage note: Always capitalize FISH when referring to the technique.
In Context
- "FISH analysis confirmed trisomy 21 in the embryo biopsy sample within 24 hours." — Laboratory report
- "The genetic counselor explained that FISH analysis would test for the five most common chromosomal abnormalities but not the full chromosome complement." — Pre-test counseling documentation