Restriction fragment length polymorphism
Restriction fragment length polymorphism (or RFLP) is a property of
DNA used in
molecular biology methods, for example,
genetic fingerprinting or
paternity testing.
Method
Usually, DNA from an individual
organism is first amplified (multiple copies are made) by the
polymerase chain reaction (PCR). It is then cut into
restriction fragments at defined positions by
restriction enzymes. The restriction fragments are then separated according to length by
agarose gel electrophoresis. The resulting gel may be enhanced by Southern blotting.
Result
The distance between the locations cut by restriction enzymes (the
restriction sites) varies between individuals: so the length of the fragments varies, and the position of certain
gel bands differs between individuals (thus
polymorphism). This can be used to genetically tell individuals apart. It can also show the genetic relationship between individuals, because children inherit genetic elements from their parents. It is also used to deterimne the relationships among
species.
- See also: genetics -- retroposon