Sterilization
Say it: ster-uh-luh-ZAY-shun
In microbiology, sterilization is any process that kills or removes all microbial life, including bacterial endospores and viruses, from an object.
UK spelling: sterilisation
Definition
What is sterilization?
In microbiology and medicine, sterilization is the complete destruction or removal of every living microorganism, including the tough endospores of bacteria such as Clostridium and Bacillus, along with viruses. It is an absolute standard: an item is either sterile or it is not. This sets it apart from disinfection, which kills most pathogens on objects but not necessarily spores, and from antisepsis, which reduces microbes on living tissue such as skin.
The most widely used method is moist heat under pressure in an autoclave, commonly at 121 degrees Celsius for 15 to 30 minutes depending on the load, or at 132 degrees for shorter times. Steam works much faster than dry heat at the same temperature because it carries more heat into the load. Items that heat would harm need other methods, such as ethylene oxide gas, hydrogen peroxide vapor or plasma, gamma or electron-beam radiation for disposable plastics, and filtration through membranes with pores of about 0.2 micrometers for heat-sensitive liquids. Because success cannot be seen, each run is checked with chemical indicators and with biological indicators, strips of highly heat-resistant spores of Geobacillus stearothermophilus that should fail to grow afterward.
Surgical instruments, implants, culture media and injected drugs all depend on it. The same word also names surgery that permanently prevents pregnancy, such as vasectomy.
Word parts
Where does the word “sterilization” come from?
- steril-
- barren, unfruitfulLatin sterilis
Related
Terms that go with it
- Aseptic techniqueAseptic technique is the set of practices that keeps microbes from contaminating sterile materials, cultures or a patient's tissues during a procedure.
- EndosporeAn endospore is a tough, dormant structure formed inside some bacteria, such as Bacillus and Clostridium, that survives heat, drying and chemicals.
- PathogenA pathogen is a microbe or other agent, such as a virus, bacterium, fungus, parasite or prion, that can cause disease in a host.
- DenaturationIn biochemistry, denaturation is the unfolding of a protein or nucleic acid by heat, acid or chemicals, which ruins its shape but not its sequence.
- AgarAgar is a jelly-forming polysaccharide extracted from red seaweeds, used above all to solidify culture media for growing microorganisms.
- BacteriumA bacterium is a single-celled prokaryote with no nucleus, found in almost every habitat on Earth, including in and on the human body.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- OpenStax Microbiology, 13.1 Controlling Microbial Growth
- OpenStax Microbiology, 13.2 Using Physical Methods to Control Microorganisms
- CDC: Sterilizing Practices, Guideline for Disinfection and Sterilization in Healthcare Facilities
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