Final answer:
Sheep blood agar (SBA) is used as a differential medium in bacteriology to distinguish bacterial species based on their hemolytic properties.
Step-by-step explanation:
Sheep blood agar (SBA) is a type of growth medium used in bacteriology, and its primary purpose is to be a differential medium. Sheep blood agar differentiates bacteria based on their hemolytic properties, that is, their ability to break down red blood cells. This break down of blood cells results in noticeable changes on the medium, such as clearing around the colonies for bacteria that exhibit complete hemolysis (beta-hemolysis), a greenish discoloration for partial hemolysis (alpha-hemolysis), and no change for those that do not cause hemolysis (gamma-hemolysis). While SBA can support the growth of many types of bacteria due to its rich nutrient content, its differential characteristic is significant for distinguishing bacterial species, particularly those that are relevant in clinical diagnostics.