Understanding Sterilization and Disinfection Sterilization eliminates all microorganisms, including spores, making an article 100% microorganism-free. In contrast, disinfection reduces the number of pathogens to a safe level but does not kill spores. Antiseptics are chemicals applied on human tissue to inhibit microbial growth without harming tissues.
Methods of Sterilization: Physical vs Chemical Physical methods include heat (dry or moist) and radiation; chemical methods involve various disinfectants. Heat is further divided into dry heat (e.g., red heat, flaming) and moist heat (e.g., boiling water). Radiation uses gamma rays for sterilizing disposable items like syringes.
Dry Heat Methods Explained Red heating involves heating metals until they turn visibly red in color to ensure sterility—used mainly for inoculation loops. Flaming superficially heats objects using a flame but isn’t highly effective compared with other techniques such as incineration or hot air ovens used primarily for glassware.
Hot Air Oven: A Key Dry Heat Method 'Hot air oven' operates at 160°C for two hours using electrically generated hot air circulated by fans—it’s ideal for sterilizing glass articles and oily substances like dusting powders while ensuring complete spore elimination through biological controls involving Bacillus subtilis subspecies niger's spores.
'Moist Heating Below Boiling Point': Pasteurization & Inspissation Techniques. 'Pasteurisation,' commonly employed milk-sterlising technique kills most bacteria except certain resistant strains under controlled sub-boiling temperatures whereas 'Inspission', another low-temperature method targets culture media containing egg-serum-sugar combinations avoiding degradation risks associated higher temperature exposure