This is a Provisional monograph.

This selective medium for faecal coliforms was formulated by Geldreich et al. (1965) and uses an elevated incubation temperature of 44.5°C together with the dye aniline blue and the selective agent rosolic acid for the identification of faecal coliform organisms. However, it has been shown that the rosolic acid can be left out of the medium without impairing its performance (Presswood and Strong, 1978; Sartory, 1980).

Dissolve the ingredients in the water by boiling. Add the rosolic acid and continue boiling for 1 min. Cool to 50°C and pour into Petri dishes. When set store at 5±3°C in airtight containers. The medium may be prepared with or without agar.