A number of passengers were severely burnt beyond recognition during a train accident. Name and describe a modern technique that can help hand over the dead to their relatives.

The technique that can help in the identification of victims is DNA fingerprinting, which distinguishes between individuals of same species by using their DNA sample/sequences.

99.9% of the base sequence in all human beings are identical, the remaining 0.1% makes every individual unique.

In this specific region called repetitive DNA sequences that are different for every individual are used for the comparative study.

This repetitive DNA is separated from the bulk DNA at different peaks during density gradient centrifugation in which bulk DNA forms major peak and other small peaks are referred as Satellite DNA.

These sequences show high degree of polymorphism and form the basis of DNA fingerprinting.

Method of DNA fingerprinting: The following steps are as follows:

A. Isolation of DNA

B. Digestion of DNA by restriction endonuclease.

C. Separation of DNA fragments by electrophoresis.

D. Transfer of separated DNA fragments to synthetic membranes.

E. Hybridisation of separated fragments using labelled VNTR probes

F. Detection of hybridised DNA fragment by autoradiography.

After autoradiography different bands are obtained which are characteristic of an individual.

The presence of similarities between the casualties and their relatives determines their relatedness on the basis of which the bodies can be handed over to their respective relatives.