What does fluorescence in situ hybridization tell you?

Fluorescence in situ hybridization (FISH) provides researchers with a way to visualize and map the genetic material in an individual’s cells, including specific genes or portions of genes. This may be used for understanding a variety of chromosomal abnormalities and other genetic mutations.

What is the principle of in situ hybridization?

The principle of in situ hybridization (ISH) is the specific annealing of a labeled probe to complementary sequences of a target nucleic acid (DNA or mRNA) in a fixed specimen, followed by detection and visualization of the nucleic acid hybrids with cytological methods.

What are the different types of fluorescent in situ hybridization?

Examples of different types of fluorescence in situ hybridisation (FISH) probes. (a) Genespecific probes target specific nucleic acid sequences on a chromosome. (b) Centromeric probes bind to repetitive sequences that are specific to the centromeric regions.

What does FISH test detect in pregnancy?

The test does not detect all chromosomal abnormalities; this FISH test specifically looks at chromosomes 21, 18, 13, X and Y. This enables the FISH test to detect most of the common chromosomal abnormalities, particularly Down syndrome. The FISH test is also able to determine the sex of the baby.

What are the advantages of fluorescence in situ hybridization?

FISH technology offers three major advantages including high sensitivity and specificity in recognizing targeted DNA or RNA sequences, direct application to both metaphase chromosomes and interphase nuclei, and visualization of hybridization signals at the single-cell level.

What are limitations of fluorescence in situ hybridization?

The main limitation of this protocol is the short-lived nature of the fluorescent signal. Unlike the products of enzymatic reactions, fluorescence vanishes away over time, and bleaches out rapidly when observed under the microscope. Therefore, fluorescence-based preparations are temporary.

What is the advantage of fluorescence in situ hybridization?

FISH has the advantage that it can be used in metaphase chromosomes and interphase nuclei, and thus offers a cell-based genetic diagnosis in complementary to DNA-based molecular testing (Xu and Li, 2013).

Can FISH test wrong?

Accuracy and limitations. Prenatal interphase FISH testing is highly accurate, with reported false-positive and -negative rates usually less than 1%. The main problem, however, is that not all specimens are informative. Uninformative rates will vary among laboratories, but rates of 3% to 10% are considered typical.