R-3A BROTH

The total bacterial count of drinking water is determined by plate count on a nutritionally rich medium. However, all organisms present are not able to grow on them, either because they are slow growers or because they can?t grow on that media. For this reason, a nutritionally reduced medium was described. R-2A Agar is a modification of this medium. Many bacteria from natural waters, which contain limited nutrients at ambient temperature, grow best on the media with less nutrient levels. They grow better at the temperatures below the routine laboratory incubation temperatures of 35 to 37?C.
R-3A Agar is a subculture medium which is used to subculture the organisms recovered on nutritionally deficient R-2A Agar. R-3A Broth is similar in composition to R-3A Agar, except agar.

for cultivation and maintenance of heterotrophic bacteria from potable water