Question

A selectable marker is used in the section of recombinants on the basis of their ability to produce colour in presence of chromogenic substrate.
(a) Mention the name of mechanism involved.
(b) Which enzyme is involved in production of colour?
(c) How is it advantageous over using antibiotic resistant gene as a selectable marker?

Answer 1

Dear student,
a) The name of mechanism is insertional inactivation.
b) The name of enzyme involved colour production is ​β- galactosidase
c) Two plates with different antibiotics are required for simultaneous plating for selection of recombinant due to antibiotic inactivation but here chromogenic substrate are used which gives blue coloured colonies when there is no insert.

Regards