Galactosidase enzyme is considered a better selectable marker. Justify the statement.
Recombinant strains can be differentiated from the non-recombinants ones easily by using this selectable marker. The selection is done on the basis of the colour change. All are grown on a chromogenic substance. Non-recombinants will change from colourless to blue while in recombinants insertional inactivation of galactosidase gene occurs. Hence, recombinants showed no colour change. This is a single step, an easy method for selection.
