Which of the following is used as control. during plasma gas sterilisation:
Ans. (b) Stearothermophilus Plasma Gas sterilization This is a type of chemical sterilization using hydrogen peroxide Hydrogen peroxide is vaporized which is then conveed into plasma. For sterilizatiion only cold plasma is used. When Hp, vapours are energized into plasma, hydroxyl and hydroperoxyl free radicals are generated along with production or UV rays. Microbicidal activity is three mechanism: Direct destruction by UV radiation Free radical induced damage Direct erosion of cells The Sterlization cycle of plasma is divided into five steps, viz: Evacuation phase Injection phase (until a 6 mg/ L F1202 level is obtained) Diffusion phase Culture and Sterilization em Plasma phase Re-establishment of atmospheric pressure:- This plasma kills all spores, bacteria, fungi, virus. However prions are not killed at all. Plasma sterilization is an alternative to ethylene oxide and is used for heat and water sensitive equipments. Sterrad sterilizers is the only plasma gas sterilizer currently approved by FDA. Control: Bacillus stearothermophilus spores are used as biological indicator.
B. Subtilis
Stearothermophilus
Cl. tetani
Cl. Perfringens