How are selective media and differential media different in their functionality? Solution Selective media allows the growth of only certain type of organisms, while inhibit the growth of all other organisms. eg:Mannitol salt agar, which allow growth of staphylococcus Differential media are used widely for differentiating closely related organisms such as gram negative bacteria particularly enterbacteriacceae Eg. McConkey agar it divide them on based of lactose producing properties into lactose fermenting other wise non lactose fermenting. ..