Restriction fragment length polymorphism

Restriction fragment length polymorphism is a property of DNA used in molecular biology methods, for example, [genetic fingerprint]? or [paternity test]?ing.

Method

Usually, DNA from an individual organism is first amplified (multiple copies made) by the polymerase chain reaction. It is then cut into restriction fragments at defined positions by restriction enzymes. The restriction fragments are then separated by length using agarose gel electrophoresis. The resulting gel may be enhanced by southern bloting.

Result

The distance between the locations cut by restriction enzymes (the "restriction sites") varies betwen individuals: so the length of the fragments varies, and the position of certain gel bands will differ between individuals (thus polymorphism). This can be used to genetically tell individuals apart. It can also show the genetic relationship between individuals, as a child will inherit genetic elements from its parents. It is also used to deterimne the relationship of species.

See also : Genetics -- Retroposon