The process of killing all living forms including spores is called sterilization and the process of killing of only the vegetative form of pathogenic bacteria as well as other microbes is disinfection.
160°C for 60 minutes.
121°C for 15 minutes at 15 pounds per square inch of pressure.
Glassware’s, metallic instruments like scissors and forceps, swabs, powder, oils and grease.
Culture media, gloves, cotton and clothes.
By High Efficiency Particulate Air (HEPA) filters.
Phenol, Lysol, Formaldehyde, Sodium hypochlorite.
Antiseptics are mild disinfectants that can be safely used on skin and mucous membranes.
Quaternary ammonium compounds are positively charged polyatomic ions, which concentrate at the cell surface and alter the physical and chemical properties of the membrane, thus killing the cell. Examples inlcude Benzalkonium chloride and Cetrimonium bromide.
The active ingredient of Dettol is chloroxylenol whereas Savlon contains a combination of Cetrimide and Chlorhexidine.
The active ingredients include Chlorhexidine, Triclosan, Thymol, Cetylpyridinium Chloride, and alcohol. The composition varies across brands.
These are the chemicals used for sterilization. They are 2% Gluteraldehyde (cidex), Ethylene Oxide (EO), Formaldehyde + steam and Beta –Propiolactone (BPL).
Tincture Iodine - 2% of Iodine in 70% alcohol - Iodophore - Povidone Iodine.
Chlorhexidine, Chloroxylenol, spirit (70% alcohol), tincture of Iodine, H2O2.
Sodium hypochlorite or Calcium hypochlorite
By treating them with disinfectant, boiling or autoclaving and finally by incineration.
Gamma rays, Electron beams and Ethylene oxide.
Gluteraldehyde or a combination of peracetic acid and hydrogen peroxide can be used.
Alkylation (hydrogen atom is replaced with an alkyl group) of protein, DNA, and RNA affects bacterial metabolism and replication. EO gas (8.5%) is often mixed with stabilizers such as CO2 (91.5%) or hydrochlorofluorocarbons (HCFC). This requires high humidity (40-80%) and long exposure times (1-6 hrs).
Ducking is a process of inactivation of Anthrax spores in animal products such as wool, hairs or bristles. It was introduced by Elmhirst Duckering, an enginer at wool factory. This is a five-step process, each lasting for 10 minutes and carried out at 40.5°C.
Porcelain filters, Seitz (asbestos) filters, Sintered glass filters, Membrane filters and HEPA filters.
It disinfects and solidifies egg and serum containing media such as LJ medium and Loeffler’s serum slope.
By fumigation with formaldehyde.
Use of high-energy radiation such as gamma rays to sterilize an article.
Rideal Walker test, Chick Martin test, Kelsey & Sykes test and in-use test.
It is also known as fractional sterilization or intermittent sterilization where steaming is done at 100°C for 30 minutes for 3 successive days. Spores that germinate after the first day are killed the next day.
Spores of Bacillus subtilis var niger is used to test hot air oven and spores of Geobacillus stearothermophilus is used to test autoclave, low temperature steam-formaldehyde sterilization and Ethylene oxide sterilization.
When Hydrogen peroxide (H2O2) is subjected to electric field, which is generated using radio frequencey energy, it becomes ionized and assumes fourth state of matter - the plasma. It contains charged ions (free radicals) , which interacts with cell components (e.g., enzymes, nucleic acids) and thereby disrupt the metabolism of microorganisms.