Fluorescence in situ hybridization (FISH)

Definition

Fluorescence in situ hybridization (FISH) is a molecular technique used to detect and localize specific DNA or RNA sequences in cells or tissue samples. It employs fluorescent probes that bind to complementary nucleic acid sequences, allowing visualization under a fluorescence microscope.

5 Must Know Facts For Your Next Test

1. FISH is commonly used for identifying the presence and location of specific genes or chromosomal abnormalities.
2. The technique involves hybridizing a fluorescently labeled probe with the target nucleic acid sequence in fixed cells or tissues.
3. FISH can be applied to both metaphase chromosomes and interphase nuclei, making it versatile in genetic diagnostics.
4. The specificity of FISH depends on the design of the fluorescent probe, which must be complementary to the target sequence.
5. FISH is widely used in clinical settings for diagnosing genetic disorders, cancer, and infectious diseases.

Review Questions

• What is the primary purpose of using FISH in microbiology?
• How does FISH enable visualization of specific DNA or RNA sequences?
• In what types of samples can FISH be performed?

Related terms

Fluorescence Microscopy:

A type of microscopy that uses fluorescence instead of traditional light to image specimens.

Hybridization:

The process by which a single-stranded DNA or RNA molecule forms a double-stranded molecule with a complementary strand.

Chromosomal Abnormality: A variation from the normal number or structure of chromosomes, often detected using techniques like FISH.