Difference between RAPD and RFLP

RAPD ( Random Amplified Polymorphic DNA)

Definition: If primers with arbitrary sequences are used for amplification, DNA segments to be amplified will be selected at random and this provides truly random sample of DNA markers and so is described as random amplified polymorphic DNA (RAPD).

RFLP : Restriction Fragment Length Polymorphism

Definition: It refers to the variation in restriction fragment lengths between individuals of a species when cut by a restriction enzyme.

RAPD ( Random Amplified Polymorphic DNA)

1. Quantity of DNA required for analysis is small (10-50 ng)

2. Same primers with arbitrary sequence can be used for different species

3. Fewer steps in procedure therefore it is rapid (Five times quicker than RFLP)

4. Technique comparatively less reliable

5. Cannot detect allelic variants

6. 1-10 loci detected

7. Method involves:

       a) extraction of DNA,

       b) amplification by PCR using random primers,

       c) gel electrophoresis of amplified DNA and visualisation of markers

RFLP (Restriction Fragment Length Polymorphism)

1. Large quantity of purified DNA required i.e. 2-10 ug

2. Different species specific probes are required.

3. Comparatively slower processing due to more steps involved.

4. Technique comparatively more reliable

5. Can detect allelic variants

6. 1-3 loci detected

7. Method involves:

       a) digestion of extracted DNA by restriction enzymes,

       b) gel electrophoresis of fragments,

       c) southern blot by specific probes and detection of specific sequences