Blood Agar	Chocolate Agar	MacConkey Agar
Blood Agar This general purpose non-selective medium is used in almost all routine culture procedures. It support the growth of most medically significant organisms (notable exceptions being Haemophilus and Neisseria species). It is a differential medium in the sense that the type of hemolysis produced by some species can be used for preliminary indentification.	Chocolate Agar This medium is blood agar which has been enriched by lysing the red blood cells and making their contents available to organisms growing on the medium. Two important species: Haemophilus influenza and Neisseria gonorrheae will grow on chocolate agar but not on ordinary agar.	MacConkey Agar This is a selective and differential medium for the cultivation of non-fastidious gram negative bacilli. It lacks specific growth factors needed by some organisms and contains inhibitory substances which prevent the growth of others. its purplish color is provided by neutral red, a pH indicator, which causes organisms which grow on the medium and ferment lactose to appear as red colonies. Rarely, MacConkey agar is used with a sugar other than lactose (e.g., MacConkey Sorbitol agar to identify E. coli O157:H7).
X.L.D. Agar	Sabouraud Agar	Mycosel Agar
X.L.D. Agar This medium, used exclusively in stool cultures, is similar to MacConkey agar (i.e. selective and differential for non-fastidious gram negative bacilli). It has an additional indicator system which causes most Salmonella strains to grow as black colonies. The red color is caused by phenol red pH indicator.	Sabouraud Agar The low pH of this medium makes it partially selective for fungi. However, many bacteria will also grow slowly on it.	Mycosel Agar This medium is made selective for fungi by the addition of antibacterial agents. These agents allow the uninhibited growth of some fungi but prevent the growth of others.