Arrange the given steps of DNA fingerprinting in the sequence from in…

The correct answer is Option (3) → (B), (A), (D), (C)

(B) Isolation of DNA — first. DNA is taken out of the cells of the sample, for example blood, hair roots or skin.

(A) Digestion of DNA by restriction endonuclease — second. Restriction enzymes cut the DNA into fragments. The fragments are then separated by size by gel electrophoresis.

(D) Transferring (blotting) of separated DNA fragments to synthetic membrane — third. The separated fragments are blotted from the gel onto a membrane of nitrocellulose or nylon, where they can be probed.

(C) Hybridisation using labelled VNTR probe — last. A labelled VNTR probe binds to the matching fragments on the membrane. The bound fragments are then detected by autoradiography.

NCERT Extract:
DNA Fingerprinting – “… The technique of DNA Fingerprinting was initially developed by Alec Jeffreys. He used a satellite DNA as probe that shows very high degree of polymorphism. It was called as Variable Number of Tandem Repeats (VNTR). The technique, as used earlier, involved Southern blot hybridisation using radiolabelled VNTR as a probe. It included
(i) isolation of DNA,
(ii) digestion of DNA by restriction endonucleases,
(iii) separation of DNA fragments by electrophoresis,
(iv) transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon,
(v) hybridisation using labelled VNTR probe, and
(vi) detection of hybridised DNA fragments by autoradiography.”