|Columbia agar||13 g|
|Ferric ammonium citrate||0.5 g|
|Esculin (aesculin)||0.8 g|
|Dextrose (glucose)||0.5 g|
|Lithium chloride||15.0 g|
|Phenol red||0.08 g|
|Distilled water||1000 ml|
|Polymyxin B sulfate||10 mg|
|Distilled water||2 ml|
To make 500 ml of medium, weigh 34.4 g basal medium powder (all ingredients except the three selective agents) and suspend in 500 ml distilled water. Sterilize by autoclaving at 121°C for 15 min. Dissolve the selective agent supplement mixture in sterile distilled water at 17.5 mg/ml and filter sterilize. Add 1 ml selective agent supplement solution to 500 ml sterile basal medium that has been cooled to 50°C. Mix gently and pour plates. Final pH, 7.2 ± 0.1.
*NOTE: The basal medium powder and lyophilized supplement mixture are available commercially; follow the manufacturer's instructions for preparing the medium.
Original Source: Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.