The transfer of denatured DNA from Agarose gel to Nitrocellulose Blotting or Filter Paper technique was introduced by Southern in 1975 and this technique is called Southern Blotting Technique.
Steps:
The transfer of DNA from agarose gel to nitrocellulose filter paper is achieved by Capillary Action.
A buffer Sodium Saline Citrate (SSC) is used, in which DNA is highly soluble, it can be drawn up through the gel into the Nitrocellulose membrane. By this process ss-DNA becomes ‘Trapped’ in the membrane matrix. This DNA is hybridized with a nucleic acid and can be detected by autoradiography. Autoradiography – A technique that captures the image formed in a photographic emulsion due to emission of light or radioactivity from a labelled component placed together with unexposed film.