Question

In blue-white screening, what do blue colonies represent?

Answer 1

Answer:

The correct option is : cells containing empty plasmid vectors

Explanation:

The blue-white screen is a technique which involves the rapid identification of the recombinant bacteria in a vector-based molecular cloning experiment. In this method, a DNA ligated vector is inserted in a host cell which is viable for transformation and grown in presence of X-gal.    

The cells that are transformed with the vectors having the recombinant DNA produce the white colonies. Whereas, the cells transformed with empty vector i.e. the non-recombinant plasmids, produce the blue colonies.