R2A Agar Eur. Pharma. 1071 Condalab

R2A AGAR was developed for bacteriological plate counts of treated potable water, being able to recover the stressed chlorine-treated bacteria. Nutritionally rich mediums suppress these slow growing bacteria, whereas a low nutrient medium, such as R2A Agar, in combination with a lower incubation temperature and longer incubation time, stimulates the growth of stressed and chlorine-tolerant bacteria. Proteose peptone and Casein Hydrolysate provide nitrogen, vitamins, minerals, and amino acids essential for growth. Yeast extract is the source of vitamins, particularly of the B-group. Dextrose is a source of fermentable carbohydrate as an energy source; Starch absorbs toxic metabolic by products and thereby aids the recovery of injured organisms. Sodium pyruvate increases the recovery of stressed cells and magnesium sulphate provides divalent cations and sulphate. Dipotassium phosphate is used to balance the pH and provide phosphate and bacteriological agar is solidifying base.

R2A Agar is recommended in Standard Methods for the Examination of Water and Wastewater for pour plate, spread plate and membrane filter methods for heterotrophic counts. The European Pharmacopoeia recommends this medium for the microbial monitoring of this water during the process of production and storage in the preparation of medicines. It is also recommended for analysis of Water for preparations of extracts, water highly purified, and water purified.