Bromocresol Purple Glucose Agar
Bromocresol Purple Glucose Agar for the detection and enumeration of Enterobacteriaceae by ISO 7402, ISO 8523, ISO 21528
Principles and uses
Bromocresol Purple Glucose Agarr is used for the differentiation of Enterobacteriaceae in urine, water and food. It differentiates species on the basis of dextrose fermentation.
This medium is recommended by ISO 11059 for the confirmation of Pseudomonas spp. in milk and milk products. Bromocresol Purple Glucose Agar was also recommended by ISO 21528:2014 for the confirmation of Enterobacteriaceae.
Tryptone and Yeast extract provide nitrogen, vitamins, minerals and amino acids essential for growth. D-glucose is the fermentable carbohydrate providing carbon and energy Sodium chloride supplies essential electrolytes for transport and osmotic balance. Bromocresol purple is a pH indicator. Bacteriological agar is the solidifying agent.
The glucose-fermenting microorganisms produce yellow colonies (acid) and the non-fermenting ones, purple colonies. Colonies that are oxidasenegative and glucose-positive are confirmed as Enterobacteriaceae.
Preparation
Suspend 41.5 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Dispense into appropriate containers and sterilize in autoclave at 121°C for 15 minutes.
