The auxotrophic selection method is a genetic research technique used to select and isolate cells with a specific genetic mutation by growing mutant cells on a medium that lacks an essential nutrient that the mutant cells cannot produce. Can you identify the colonies that are his⁻, arg⁻, leu⁻ using this method?

• A. Yes, because these colonies will not be able to grow on a minimal medium that lacks histidine, arginine, and leucine respectively.
• B. No, because these colonies will be able to grow on a minimal medium that lacks histidine, arginine, and leucine respectively.
• C. No, because the presence of a mutation in any one of the three genes would still allow the colony to grow on a minimal medium that lacks histidine, arginine, and leucine.
• D. No, because the missing nutrients can be synthesized by other pathways in the mutant cells.

Answer: (A)