An analysis of chromosomal DNA using the Southern hybridization technique does not use:
- Blotting
- PCR
- Electrophoresis
- Autoradiography
Answer
(2) PCR
Solution
As per NCERT, the steps of DNA fingerprinting (Southern blot hybridisation) are:
(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 a labelled VNTR probe, and (vi) detection of hybridised DNA fragments by autoradiography.
∴ Blotting, electrophoresis and autoradiography are used, but PCR is not a step of Southern hybridisation.
Answer: (2)