Fluorescence in situ hybridization (FISH) is a laboratory technique employed to detect and localize specific DNA sequences on chromosomes. In the context of prenatal diagnostics, it offers a rapid method for identifying chromosomal abnormalities. For instance, this method can quickly determine if a fetus has an extra copy of chromosome 21, a condition known as Trisomy 21. The test utilizes fluorescent probes that bind to specific regions of the chromosome, allowing visualization and quantification of the target sequence under a microscope.
The diagnostic capability offers a significant advantage in situations where timely information is critical. Traditional karyotyping methods, while comprehensive, can take several days to produce results. This rapid turnaround time allows clinicians to provide earlier counseling and management options to expectant parents. Its development represents a significant advancement in the field of cytogenetics, providing a more efficient way to screen for certain chromosomal conditions.