Question

Arrange the various steps of DNA fingerprinting technique in the correct order
(i) Separation of DNA fragments by electrophoresis
(ii) Digestion of DNA by restriction endonucleases
(iii) Hybridization using labeled VNTR probe
(iv) Isolation of DNA
(v) Detection of hybridized DNA fragments by autoradiography
(vi) Transferring the separated DNA fragments to nitrocellulose membrane

• A. (ii) $\to$ (i) $\to$ (iv) $\to$ (vi) $\to$ (iii) $\to$ (v)
  
• B. (iv) $\to$ (i) $\to$ (ii) $\to$ (iii) $\to$ (vi) $\to$ (v)
• C. (iv) $\to$ (ii) $\to$ (i) $\to$ (vi) $\to$ (iii) $\to$ (v)
  
• D. (iii) $\to$ (v) $\to$ (iv) $\to$ (ii) $\to$ (i) $\to$ (vi)

Answer 1

Answer: (C)

(iv) $\to$ (ii) $\to$ (i) $\to$ (vi) $\to$ (iii) $\to$ (v)

The technique of DNA Fingerprinting was initially developed by Alec Jeffreys. It included: -

1. Isolation of DNA,
2. Digestion of DNA by restriction endonucleases,
3. Separation of DNA fragments by electrophoresis,
4. Transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon,
5. Hybridisation using labelled VNTR probe, and
6. Detection of hybridised DNA fragments by autoradiography.

So, the correct option is '(iii) → (v) → (iv) → (ii) → (i) → (vi)'.