Demonstration of a point mutation

Demonstration of a point mutation
by ribonuclease A cleavage
The basis for this method is that a normal DNA
strand hybridizes completely with mRNA from
that region. Completely hybridized DNA and
mRNA are protected from the effects of the
RNA-splitting enzyme ribonuclease A (ribonuclease
protection assay). Hybridization is incomplete
in the area of a mutation. In this region,
mRNA will be cleaved by ribonuclease A
(RNAase A). This can be demonstrated by
Southern blot. There will be two fragments
formed that together correspond to the size of
the completely hybridized fragment