Which of the following results is provided by northern blot analysis?
a. Detects specific base pairsb. Detects DNA molecules
c. Detects RNA molecules
d. Detects proteins
The answer is c.
Northern blotting is
analogous to Southern blotting, a technique that was first described by Edward
Southern. DNA fragments are separated on agarose gels by electrophoresis and
then transferred to nitrocellulose filters. The filters are then exposed to
labeled probes, which hybridize to the DNA fragments. Northern blotting is an
analogous procedure that uses more powerful denaturing substances to extend the
RNA molecules and ensure that their electrophoretic migration is inversely
proportional to their length. Labeled RNA or DNA segments (probes) are used to
identify particular RNA species within the size separated array. Western
blotting is a technique for detecting proteins. It uses a different type of
denaturing gel and labeled antibodies as probes to detect specific proteins.
