Fluorescence in Situ Hybridization (FISH) Probe

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 FISH?

Fluorescence in situ hybridization (FISH) is a kind of cytogenetic technique which uses fluorescent probes binding parts of the chromosome to show a high degree of sequence complementarity. Fluorescence microscopy can be used to find out where the fluorescent probe bound to the chromosome. This technique provides a novel way for researchers to visualize and map the genetic material in an individual cell, including specific genes or portions of genes. It is an important tool for understanding a variety of chromosomal abnormalities and other genetic mutations. Different from most other techniques used for chromosomes study, FISH has no need to be performed on cells that are actively dividing, which makes it a very versatile procedure.

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FISH is useful, for example, to help a researcher or clinician identify where a particular gene falls within an individual's chromosomes. The first step is to prepare short sequences of single-stranded DNA that match a portion of the gene the researcher is looking for. These are called probes. The next step is to label these probes by attaching one of a number of colors of fluorescent dye. DNA is composed of two strands of complementary molecules that bind to each other like chemical magnets. Since the researchers' probes are single-stranded, they are able to bind to the complementary strand of DNA, wherever it may reside on a person's chromosomes. When a probe binds to a chromosome, its fluorescent tag provides a way for researchers to see its location.

Generally, researchers use three different types of FISH probes, each of which has a different application:

Locus specific probes bind to a particular region of a chromosome. This type of probe is useful when researchers have isolated a small portion of a gene and want to determine on which chromosome the gene is located.

Alphoid or centromeric repeat probes are generated from repetitive sequences found in the middle of each chromosome. Researchers use these probes to determine whether an individual has the correct number of chromosomes. These probes can also be used in combination with "locus specific probes" to determine whether an individual is missing genetic material from a particular chromosome.

Whole chromosome probes are actually collections of smaller probes, each of which binds to a different sequence along the length of a given chromosome. Using multiple probes labeled with a mixture of different fluorescent dyes, scientists are able to label each chromosome in its own unique color. The resulting full-color map of the chromosome is known as a spectral karyotype.

References:

https://www.creative-biolabs.com/fluorescent-in-situ-hybridization-FISH.html

https://www.theinsightpartners.com/reports/fish-probe-market