What differentiates selective media from differential media?

Selective media is specifically designed to allow the growth of certain types of microorganisms while inhibiting the growth of others. This selective capability is often achieved by incorporating specific nutrients or inhibitory agents that favor the desired microorganisms. For example, in a selective medium that contains antibiotics, only those microbes that are resistant to the antibiotic will thrive, while those that are sensitive will not grow.

On the other hand, differential media serve a different purpose; they are formulated to distinguish between different types of microorganisms based on their metabolic characteristics. Differential media often contain indicators that lead to visible changes in the medium, such as color changes, depending on the biochemical activities of the organisms growing on the medium.

Thus, the correct answer highlights the primary function of selective media in promoting the growth of certain organisms while inhibiting others, which is fundamental to isolating and identifying specific microbes in a mixed population.