Question

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.

A criminal blew himself up in a local market when was chased by cops. His face was beyond recognition. Suggest and describe a modern technique that can help establish his identity.

During a fire in an auditorium a large number of assembled guests got burnt beyond recognition. Suggest and describe a modern technique that can help hand over the dead to their relatives

Answer 1

The technique that will help the authorities to establish the identity of the dead is known as DNA finger printing.

Basis of DNA Fingerprinting - DNA fingerprinting is a method for comparing the DNA sequences of any two individuals. 99.9% of the base sequences in all human beings are identical. It is the remaining 0.1% that makes every individual unique. In this, certain specific regions called repetitive DNA sequences that are different for every individual are used for comparative study. This repetitive DNA is separated from the bulk DNA as different peaks during density gradient centrifugation in which bulk DNA forms major peak and the other small peaks are referred to as satellite DNA. These sequences show high degree of polymorphism and form the basis of DNA fingerprinting.

Methodology of DNA fingerprinting-
The DNA fingerprinting technique involves following steps:

(i) Isolation of DNA
(ii) Digestion of DNA by restriction endonucleases
(iii) Separation of DNA fragments by electrophoresis
(iv) Transfer of separated DNA fragments to synthetic membranes
(v) Hybridisation of separated fragments using labelled VNTR probes
(vi) Detection of hybridised DNA fragments by autoradiography

After autoradiography, different bands are obtained which are characteristics of an individual.

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