Indicator used in autoclave is ?

Ans. is 'b' i.e., Bacillus stereothermophilus Biological indicators . Biological indicators are standardised preparations of microorganisms used to assess the effectiveness of a sterilization process. . They usually consist of a population of bacterial spores placed on an ine carrier, for example a strip of filter paper, a glass slide or a plastic tube. . Most commonly, spores of Bacillus stereothermophilus (Geobacillus stearothermophilus) are used. Spores of Bacillus subtilis and Bacillus pumilis are alse used. . For various methods of sterilization following biological indicators are used :- Type of Sterilization Spore used Moist heat (autoclave) Bacillus stearothermophilus Dry heat (hot air oven) Bacillius subtilis Ionizing radiation Bacillus pumilis Gas sterilization (ethylene oxide) Bacillus subtilis Plasma sterilization Bacillus stearothemophilus