Question

Select the correct sequences of steps in DNA fingerprinting involving Southern blot hybridisation using radiolabeled 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 hybridisation 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. II, I, V, VI, IV, III
  
• D. V, I, VI, III, IV and II

Answer 1

The correct option is B II, VI, V, III, I and IV


DNA fingerprinting
DNA fingerprinting is the technique used for determining nucleotide sequences of certain areas of DNA which are unique to an individual.

Steps of DNA fingerprinting
1. Isolation of DNA from the biological sample such as hair bulb, saliva, sperm, blood (leucocytes).
2. Digestion of isolated DNA with restriction endonucleases.
3. Separation of digested DNA fragments by agarose gel electrophoresis.
4. Transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon.
5. Hybridisation of transferred DNA fragments using radiolabeled VNTR probe.
6. Detection of hybridised DNA fragments by autoradiography.

Diagramatic representation of DNA fingerprinting
Final answer
(B) II, VI, V, III, I and IV