The researcher has a bacterial colony containing 500 cells that are a mixture of wild-type and auxotrophic mutants. To identify the auxotrophic mutants, the researcher performs replica plating. The colony is streaked onto a complete medium and allowed to grow. Afterward, a sterile velvet pad is placed onto the bacterial colony, picking up some of the bacterial cells. The pad is then used to make a replica of the bacterial colony onto two different media: minimal media and minimal media supplemented with the nutrient that the auxotrophic mutants require.

What is the purpose of replica plating in identifying auxotrophic mutants in a bacterial colony?