Question

Why do forensic labs analyze non-coding DNA?

Answer 1

1. It is known that 99% of DNA in all human beings is the same.
2. It is only about 0.001% of DNA which is different that makes each individual unique.
3. Non-coding DNA is the DNA which does not code for any proteins, but is inherited from the parents.
4. Non-coding DNA contains 20-100 base pairs of repetitive sequences which are called as Variable Number Tandem Repeat (VNTR).
5. They are also called as Mini-satellites.
6. The length of the DNA fragment containing these VNTR’s varies in each individual.
7. Each individual carries a specific sequence of VNTRs.
8. The probability of two individuals having the same VNTR sequence is one in 30 million.
9. Thus, the pattern of VNTRs serves as the basis for DNA fingerprinting technique.
10. Hence, forensic labs analyse non-coding DNA in cases of criminal investigation to compare and match the sequences of DNA obtained from the crime scene with the suspect.