R2A agar (Reasoner's 2A agar) is a culture medium [1] developed to study bacteria which normally inhabit potable water. [2] These bacteria tend to be slow-growing species and would quickly be suppressed by faster-growing species on a richer culture medium. [3]
Since its development in 1985, [3] it has been found to allow the culturing of many other bacteria that will not readily grow on fuller, complex organic media.[ citation needed]
Final pH 7.2 ± 0.2 @ 25 °C