Zoology - Biotechnology - Principles and Processes Question with Solution | TestHub

A recombinant DNA is inserted within the coding sequence of an enzyme, ß-galactosidase. This results in the inactivation of the gene for the synthesis of this enzyme, which is referred to as insertional inactivation. The presence of a chromogenic substrate gives blue coloured colonies if the plasmid in the bacteria does not have an insert. Presence of insert results into insertional inactivation of the ß-galactosidase gene and the colonies do not produce any colour, these are identified as recombinant colonies.