Question

1. DNA fragments from a gel are transferred to a nitrocellulose paper during the procedure called Southern blotting. What is the purpose of transferring the DNA from a gel to a nitrocellulose paper

Answer 1

After the previous processes, the DNA is blotted from the Agar Agar gel to nitrocellulose paper. This is done because in the next step, radioactive probe is added to the DNA fragments to make it visible in Xray film.

Explanation:

DNA finger printing is a very important process in Forensic medicine as DNA finger printing is the only 100% proof of one's identity.

In DNA finger printing, first the DNAs are taken in Agar Agar gel on one side and restriction endonuclease enzymes are applied that will cut the DNA in particular sequences. These cut pieces are then separated using gel electrophoresis. After the gel electrophoresis, the gel is then blotted on a nitrocellulose paper so that they can be washed and treated with radioactive probes that will get attached with the cut pieces of the DNA and make them visible in Xray film. Then this paper is put onto xray film and the pattern is noted.