Samples with colonies of Clostridium perfringens
6. In the case of each plate, 10 characteristic colonies of Clostridium perfringens shall be subcultured on to a further SF agar plate. If there are less than 10 colonies on the plate, all characteristic colonies shall be subcultured on to the further plate. The plates shall be incubated anaerobically at 37°C±1°C for 20 hours±2 hours.