<prompt> The indicator used in the autoclave is?Clostridium tetaniBacillus stereothermophilusBacillus pumilisBacillus subtilis Var Niger  <response>: Sterilization control: for determining the efficacy of moist heat sterilization, spores of Bacillus stearothermophilus are used as the test organism. This is a thermophilic organism with an optimum growth temperature of 55-60oC and its spores require exposure of 12 minutes at 121oC to be killed REF:Ananthanarayan Panickers Textbook of Microbiology 8th edition pg no:34 