A biotechnologist wanted to create a colony of E.coli possessing the plasmid pBR322, sensitive to Tetracycline. Which one of the following restriction sites would he use to ligate a foreign DNA ?

Options

A. Sal I
B. Pvu I
C. EcoRI
D. Hind III

Answer

A

Explanation

When an alien gene is ligated at the Sal I site of tetracycline resistance gene in the vector PBR322, the recombinant lose tetracycline resistance due to insertion of the for eign DNA.