The growth medium for ethylene oxide and dry heat spore strips has been developed to incubate Bacillus atrophaeus spores (# 9372) to easily monitor growth. After sterilization the spores, e.g. spore strips are aseptically transferred into the growth medium on a sterile bench and incubated at 33 - 37°C afterwards.

The medium contains a pH-indicator that shows bacteria growth quicker than conventional media. If not all spores were inactivated during the sterilization process, the germs replicate and produce acids. The resulting pH changes the colour of the liquid from green to yellow.