R2A AGAR, MODIFIED

This medium is recommended in standard methods for pour plate, spread plate and membrane filter methods for hetrotrophic plate count. It was developed by Reasoner and Geldreich for bacterial plate counts of treated potable water. The HPC, heterotrophic plate count formerly known as the standard plate count is a procedure for estimating the number of live bacteria in water and measuring changes during water treatment in distribution systems or in swimming pools. The use of low nutrient media favours growth of injured or stressed organisms at longer incubation periods as compared to the use of high nutrient media. As compared to Tryptone Glucose Agar or Standard methods agar, R2A agar has been reported to give improved recovery of stress and chlorine tolerant bacteria from drinking water systems.

for the enumeration and cultivation of bacteria from potable water