Biotechnology and Bioinformatics (1+1)

Southern blotting

Southern blotting is the transfer of DNA fragments from an electrophoresis gel to a membrane support resulting in immobilization of the DNA fragments. So the membrane carries a semi permanent reproduction of the banding pattern of the gel. Southern hybridization technique was developed by E.M. Southern (1975)

There are three methods of transfer of DNA fragments from agarose gels to solid support

1. Capillary transfer

2. Electrophoretic transfer

3. Vacuum transfer

Vacuum transfer is the most efficient and rapid method. Depurinated and denatured DNA is transferred in approximately 30-45 mins from gels of normal thickness (4-5 mm) and normal agarose concentration (0.7-1.0%)