restriction fragment length polymorphism (RFLP)

restriction fragment length polymorphism (RFLP)

when the restriction endonuclease DNA fragment patterns of organisms of the same type or species are compared minor differences in the patterns are observed which are produced by gain or loss of restriction sites or by insertion or deletion of DNA to make a particular fragment larger or smaller. Where a large amount of DNA, such as all the chromosomal DNA from a cell, is digested with a restriction enzyme and separated on an agarose gel, the fragments can be transferred to a nylon membrane (Southern blot) and probed with a particular probe, usually directed at repetitive DNA sequences. The pattern so obtained is unique to a particular individual. Called also restriction endonuclease DNA fingerprints. See also parentage testing.