The ampoules are filled with 1.5 or 0.25 ml growth medium and Geobacillus stearothermophilus spores of different populations:
- 10^5 CFU/ampoule version conforms with standard EN ISO 11138-1 + 3 and USP
- 10^6 CFU/ampoule version conforms with standard EN ISO 11138-1 + 3, USP and additionally EP (European Pharmacopeia), that requires a population of at least
5 x 10^5 CFU/indicator for steam sterilization processes.
The ampoules are used for monitoring of liquid or waste sterilization processes. The ampoule should be placed in an area considered to be the most difficult to sterilize: directly in fluids, in the centre of packs or inside of waste bags. Both versions contain a pH-indicator colour that changes colour during incubation at 55 - 60°C if not all spores were inactivated during the sterilization process.
A microbiological laboratory is not required but only an incubator which is available with aluminium block (insert) for ampoules.