Question

What is the correct time for carrying out the alkaline phosphatase treatment?

(a) After the cutting of vector has been done

(b) Before the insert DNA and the vector are mixed

(c) After the cutting of vector has been done but before the insert DNA and vector are mixed

(d) After the mixing of insert DNA and vector

This question was addressed to me by my school teacher while I was bunking the class.

The query is from Modifications in Cloning Methods, Linkers,  Adaptors and Cassettes in portion Simple Cloning of Genetic Engineering

Answer 1

Right option is (c) After the cutting of vector has been done but before the insert DNA and vector are mixed

Easy explanation: The alkaline phosphatase treatment is carried out after the cutting of DNA has been done but before the mixing of insert DNA and vector has been done. There should be no traces of the enzyme left after the insert DNA has been added.