Which Probing Technique Detects DNA Immobilized on a Membrane Using

Question

Which probing technique detects DNA immobilized on a membrane using labeled DNA fragments?
A) northern blot
B) southern blot
C) western blot
D) polyacrylamide gel electrophoresis in SDS
E) isoelectrofocusing

Accepted Answer

Southern blotting is the probing technique that uses labeled DNA fragments to detect the presence of specific DNA sequences immobilized on a membrane after separation via gel electrophoresis. Northern blotting is similar but is used to detect RNA, while western blotting detects proteins. Polyacrylamide gel electrophoresis in SDS is a technique used for protein separation, and isoelectric focusing separates proteins based on their isoelectric point.