Restriction fragment length polymorphism

RFLP restriction fragment length polymorphism abbreviated (Restriction Fragment Length Polymorphism ) is a method for determining the genetic fingerprint. In this case, DNA fragments are cleaved by restriction enzymes and sorted using a gel according to their length, thus forming two different DNA samples can be compared.

Properties

The RFLP method finds in the law enforcement or paternity testing application. She was the first inexpensive method of comparing the relationship of two samples, but increasingly by other biochemical methods such as DGGE or TGGE, the phospholipid analysis, the polymerase chain reaction (some with DNA sequencing ), RAPD, the STR ​​analysis, the SSCP analysis or further developments of RFLP as AFLP, t- RFLP, ARISA, ARDRA replaced.

RFLPs are used, inter alia, as genetic markers in genetic mapping because they are more likely inherited together, the closer they are together. They are also used to search for quantitative trait loci, ie chromosome segments with influence on the expression of a quantitative trait, as well as in Southern blots.

A more specific application is the T-RFLP ( Terminal RFLP). The target gene in the PCR ( Polymerase Chain Reaction) with one (or both) of fluorescence-labeled primers are amplified. The amplification products are digested with a restriction enzyme and analyzed by an automated sequencer. This only detects the fluorescent fragments (the terminal ). Application, for example for determining in a sample of the diversity or diversity comparisons along a gradient.

Principle

A sequence containing a cleavage site for a restriction enzyme in the sequence with the person 2 does not occur in this example, Person 1. These sequences are now cut with a restriction enzyme, the two fragments created in individual 1 and individual 2 fragment. Now, if the lengths of the sequences compared, an RFLP can be found, the fragments are of different lengths, the locus is polymorphic.