試題詳解

6. Regarding molecular cloning using restriction enzyme and ligase.
(A) Blunt end is clean and thus easier to be ligated.
(B) Ligase also mediates joining of sticky ends by catalyzing the formation of hydrogen bonds.
(C) Two sticky ends with complementary overhangs can be perfectly ligated but the restriction enzyme recognition site is not necessarily restored.
(D) Restriction enzyme more efficiently cuts at the ends of DNA fragments.
(E) Phosphatase treatment of both digested vector and digested insert reduces self-ligation so that correct ligation is enhanced.