(a) A recombinant vector with a gene of interest inserted within the gene of -galactosidase
enzyme, is introduced into a bacterium. Explain the method that would help in selection of
recombinant colonies from non-recombinant ones.
(b) Why is this method of selection referred to as ''insertional inactivation"?
(a) Chromogenic substrate is used to identify recombinants and non-recombinants. Blue
coloured colonies of bacteria show no recombination and colonies with no blue colour
show presence of recombinants.
(b) In this a recombinant DNA is inserted within the coding sequence of an enzyme,
-galactosidase. This results into inactivation of the enzyme which is referred to as