A hybridization probe is a short piece of DNA (on the order of 100-500 bases) that is denatured (by heating) into single strands and then radioactively labeled, usually with phosphorus (32P or 33P). The radioactive phosphorus is incorporated into the phosphate group of the individual nucleotides of DNA, which are incorporated into the backbone of the DNA strands by incubation with a polymerase enzyme. This creates a short piece of radioactively labeled DNA with known sequence that will hybridize with any complementary nucleic acid strands. The probe can be used in a Northern or Southern blot to detect genes or RNA transcripts with which it has homology (a region with similar base pair sequence). The location of the hybridization probe on the blot can then be determined by creating an image by exposing the hybridized blot to a phosphorus screen (similar to developing an x-ray image).

External links

• Immunohistochemistry - In Situ Hybridization

Molecular biology

雜交探針