Agar Types

Front 1

Mannitol Salt Agar

Back 1

Isolates Staphylococcus that are halophilic/halotolerant, as from skin.

Virulent strains ferment mannitol forming a yellow halo around colonies.

Front 2

Plate Count Agar

Back 2

Many heterotrophic bacteria can grow on it.

Contains glucose, tryptone (protein) and yeast extract (vitamins and amino acids).

Front 3

MRS Lactobacilli Agar

Back 3

Isolates lactobacilli and yeast, like those in the human mouth or on cheese.

Low pH and high concentration of acetic acid inhibits other growth.

Front 4

Tinsdale Agar

Back 4

Isolates corynebacteria and other diptheroids, like those in the throat.

Contains cystein, thiosulfate, and potassium tellurite.

Streptococcus pyogenes shows up as pinpoint black colonies with no halo.

Front 5

Chocolate Agar

Back 5

Is blood agar that has been heated to break open some red blood cells.

Isolates Neisseria and Haemophilus.

Front 6

Blood Agar

Back 6

Contains red blood cells.

Isolates alpha- and beta-hemolytic Streptococcus and Staphylococcus.

Beta-hemolytic Strep. like S. pyogenes (strep throat) will show up with a clearing around them.

Alpha-hemolytic Strep. like S. pneumonia (pneumonia) will show up with green halo around them.

Front 7

Mitis Salivarius Agar

Back 7

Isolates streptococci.

Contains tellurite to suppress other growth.

Strep. show up as blue pinpoint or large gumdrop-shaped colonies.

Front 8

R2A Agar

Back 8

More "nutritionally defined" than plate count agar.

Contains less nutrients.

Isolates bacteria that live in midstream water where there are less nutrients.

Front 9

Cooke Rose Bengal Agar

Back 9

Isolates fungi.

Contains rose bengal dye and streptomycin (30ug/l) which are antibacterial.

Contains glucose for carbon source.

Front 10

Vogel-Johnson Agar

Back 10

Isolates Staphylococcus aureus.

Contains potassium tellurite, lithium chloride, glycine, mannitol, and phenol red (pH indicator).

S. aureus appear as pinpoint black colonies, with yellow halo if they ferment mannitol.