RFLP -->
restriction fragment length polymorphism
medical dictionary

<molecular biology, technique> A method that allows familial relationships to be established by comparing the characteristic polymorphic patterns that are obtained when certain regions of genomic DNA are amplified (typically by PCR) and cut with certain restriction enzymes.

The variation in the length of DNA fragments produced by a restriction endonuclease that cuts at a polymorphic locus. Such variations are generated by mutations that create or abolish recognition sites for these enzymes.

This is a key tool in DNA fingerprinting, reflecting the existence of different alleles in the individual. Restriction fragment length polymorphism mapping is also used in plant breeding to see if a key trait such as disease resistance is inherited.

In principle, an individual can be identified unambiquously by restriction fragment length polymorphism hence the use of restriction fragment length polymorphism in forensic analysis of blood, hair or semen).

Similarly, if a polymorphism can be identified close to the locus of a genetic defect, it provides a valuable marker for tracing the inheritance of the defect.

Synonyms: DNA fingerprinting.

Acronym: RFLP

(12 Jan 1998)