Question

Explain why Southern blotting is effective at identifying if a DNA sample belongs to an individual. Also explain why the technique may not be effective when used at a crime scene.

Answer 1

Southern blotting often uses to identify specific small DNA sequences (tandem repeats) in an individual and that can be compared to another one person and there is significant different in the non-coding DNA of two individuals except mono zygotic twins. Such sequences known as VNTR or STR (small sequences of DNA) can be investigated through southern blotting with the help of radio active probe. This technique is an intergarl part of DNA fingerprinting. This technique being used for various areas of science including paternity dispute and forensic science. Although this is very effective approach but still have some limitations like it is a time taking procedure and need sufficient quantity of DNA (now a days PCR use to amplify DNA first).