CLED Agar, Bevis (Powder)

CLED Agar (Cystine-Lactose-Electrolyte-Deficient) media was first formulated by Sandys and later modified by Mackey and Sand. In the presence of the indicator dye, bromthymol blue, lactose-fermenting bacteria produce yellow colonies while non-lactose fermenting bacteria give blue colonies. Bevis incorporated an additional dye, acid fuchsin, causing lactose fermenting bacteria to produce bright pink colonies and non-lactose fermenting bacteria to show colorless. This medium supports the growth of urinary pathogens and give good colonial differentiation of these bacteria. Since there are no salts (electrolyte-deficient) in this media the swarming of Proteus sp. is suppressed. Various authors have used CLED Agar, Bevis as a dip inoculum transport medium for urine specimens. A quantitative count method for urine cultures called the Drop Plate method was devised by Neblett.

Directions per Liter:

Dissolve 36.2grams per liter of distilled/ deionized (DDI) water, heating with stirring until completely solubilized.

Dispense into appropriate containers, loosen caps and autoclave for 15 minutes at 121ºC (15psi).

Component	g/liter
Pancreatic Digest of Gelatin	4
Beef Extract	3
Casein Digest Peptone	4
Lactose	10
L-Cystine	0.128
Bromothymol Blue	0.02
Acid Fuchsin	0.1
Agar	15
	Total: 36.2g/Liter

Storage and Stability:

Store powdered media at RT. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept at 4°C and used within a short period of time.