Question

Following the collision of two trains a large number of passengers are killed. A majority of them are beyond recognition. Authorities want to hand over the dead to their relatives. Name a modern scientific method and write the procedure that would help in the identification of kinship.

Answer 1

DNA fingerprinting is the modern scientific method used for the identification of kinship.

Procedure of DNA Fingerprinting

• Variable Number of Tandem Repeats (VNTR) are satellite DNAs that show high degree of polymorphism.​ They are used as probes in DNA fingerprinting.

• Firstly, DNA from an individual is isolated and cut with restriction endonucleases.

• Fragments are separated according to their size and molecular weight through gel electrophoresis.

• Fragments separated through electrophoresis gel are blotted (immobilised) on a synthetic membrane such as nylon or nitrocellulose.

• Immobilised fragments are hybridised with a VNTR probe.

• Hybridised DNA fragments can be detected by autoradiography.

• VNTRs vary in size, ranging from 0.1 to 20 kb. Hence, in the autoradiogram, a band of different sizes will be obtained.

• These bands are characteristics of an individual. They are different in each individual, except in the case of identical twins.