Selected and Differential Media

Define

Selective Media Differential Media Enriched Media

Blood Agar Plate (BAP)

Differential Enriched Use

Growth Hemolysis

Alpha Beta Gamma

C-CNA

Selective Differential Results

Gram (+) Colistin Naldixic acid

Blood Hemolysis

MSA

Selective Differential Results

Halotolerant (7.5% NaCl) CH2O: Mannitol pH

phenol red Fermentation

Acid Yellow

MAC Selective Differential Results

Gram (-) CV Bile Salts

Lactose pH indicator

Neutral red indicator Ferment = pink/red No acid = colorless

EMB

Selective Differential Results

Gram (-) Eosin dye MB dye

Lactose Some acid = pink Large acid = green No acid = colorless

Set Up

One plate for each group Label quadrants as lab

book indicates for each plate

Cultures on cart Anaerobic Gas Pack

BAP C-CNA

All others aerobic 37°C

BAP results

Sheep blood enriched Growth most all microbes Fastidious Differential

GP Hemolysins Hemolysis types

Gamma Alpha Beta

Hemolysis

No hemolysis

C-CNA results

Selective Growth GP

Colistin Nalidixic acid

Differential Hemolysis

MSA results

Selective 7.5% NaCl Staphylococcus spDifferential Mannitol fermentation phenol red yellow

MAC results

Selective: GN CV Bile Salts

Differential Lactose fermentation NF = colorless Coliforms

Neutral red pink

EMB results

Selective: GN Dyes

Eosin MB

Differential Lactose fermentation NF = colorless Acid production

Small = pink Large = metallic green