We typically do not collect colonial morphology from a MacConkey agar (MAC) plate because the ingredients in the MAC agar can interfere with the growth and appearance of the colonies. MAC agar contains crystal violet and bile salts, which inhibit the growth of Gram-positive bacteria and allow only the growth of Gram-negative bacteria. This selective nature of MAC agar can alter the appearance of the colonies and make it difficult to accurately assess and identify the colonies based on their colonial morphology. It is better to use a non-selective media for collecting colonial morphology.
