Question

Select the correct sequences of steps in DNA fingerprinting involving southern blot hybridization using radiolabelled VNTR as probe.
I. Hybridisation using labelled VNTR probe
II. Isolation of DNA
III. Transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon
IV. Detection of hybridized DNA fragments by autoradiography
V. Separation of DNA fragments by electrophoresis
VI. Digestion of DNA by restriction endonucleases

• A. I, V, VI, II, III and IV
• B. II, VI, V, III, I and IV
• C. V, I, VI, III, IV and II
• D. II, I, V, VI, IV and III

Answer 1

Answer: (B)

II, VI, V, III, I and IV

DNA fingerprinting involves the following steps:

1. Isolation of DNA from sample cell.

2. If DNA is less in amount, it can be amplified using polymerase chain reaction (PCR).

3. Digestion of this DNA by restriction endonucleases.

4. These DNA fragments are electrophoresed in agarose gel. These fragments can be visualized by the EtBr-UV system.

5. Separated DNA fragments are transferred to nitrocellulose membrane using southern blotting.

6. Probing for VNTRs is done using labeled DNA probes.

7. The hybridized fragments can be detected by autoradiography.

Hence, The correct option is B.