For selection of recombinants, insertion | Class 12 Biology Chapter Biotechnology Principles and Process, Biotechnology Principles and Process NCERT Solutions

In the selection of recombinant plasmids, antibiotic resistant genes are used as selectable markers which is very difficult. Insertion inactivation requires the two alternative plating of culture media and possess alternative selective markers that have been developed to facilitate the methodology; these alternative methods are used to differentiate between recombinants and non- recombinants. In the presence of chromogenic substrate non- recombinants produces colour. And, recombinant- DNA is integrated into the coding sequence of β- galactosidase enzyme, through which the enzyme get inactivated, is known as insertional inactivation. Non- recombinant plasmid of bacteria gives blue colour in the presence of chromogenic substrate and the recombinant plasmid leads into insertional inactivation of β- galactosidase enzyme so that colour will not develop and hence, the recombinant colonies are identified.