Definition: It is the process in which articles to be sterilized are repeatedly exposed to steaming at 10C for 20-45 min for 3 successive days with incubation of the articles at 3C for 24 hours in between.
Process: First exposure to 10 C for 30 min→ Vegetative bacteria are destroyed, but spore remain→ Incubation (not freezing) for overnight. May be 3C→ Germination of spores→ Second exposure to 10 for 30 min→ Vegetative bacteria are destroyed → But few spore may remain→ Incubation → Germination→3 rd exposure→ All are destroyed.
Articles: Media containing:
- Any other heat labile substance (Peptone water 1% CHO)