Fecal Coliforms Agar (m-FC AGAR)

In the beginning the faecal coliforms, derived from the intestinal tract of warm-blooded animals, were separated from the nonfaecal coliforms by use of elevated temperature tests, which needed confirmatory MPN procedure in addition. GELDREICH et al. published the development of a Faecal Coliform (FC) Medium for the membrance filtration technique using an incubation temperature of 44.5 °C ± 0.2 °C. m-FC Agar is supplemented with rosolic acid and incubated at 44.5 °C ± 0.2 °C for 24 h.
Peptone and yeast extract serve as nutritious source and bile salts are added to inhibit accompanying Gram-positive flora. Lactose can be fermented by faecal coliforms at the elevated temperature to form blue colonies on the ready medium (agar base plus rosolic acid), whereas other organisms show grey colonies.

Preparation
Suspend 52 g in 1 litre of distilled or deionized water and heat to boiling to dissolve completely. Add 10 ml of a 1 % solution of rosolic acid in 0.2 N NaOH. Continue heating for 1 minute with frequent agitation. Do not autoclave! Cool to 45-50 °C. Dispense 4 ml amounts into Petridishes (Æ 50-60 mm) and allow to solidify. Cool to 50 °C and pour plates. pH: 7.4 ± 0.2 at 25 °C. The plates are clear and blue to violet