Selectable markers help us in identifying and eliminating non transformed cells during gene cloning. Explain how the gene for a – galactosidase enzyme works as selectable marker?
In this method, a recombinant DNA is inserted within the coding sequence of an enzyme – galactocidase.
Then the enzyme is inactivated, which is called insertional inactivation. The bacterial colonies whose plasmids do not have an insert, produce blue colour, but those with an insert or recombinants, do not produce any colour.
