The term for procedures that prevent contamination by microbes is asepsis.
Asepsis refers to maintaining conditions free from disease-causing microorganisms and to the practices used to prevent their introduction or spread. In healthcare, aseptic procedures can include hand hygiene, sterile gloves and gowns, disinfected or sterilized instruments, protective barriers, and careful preparation of an operative field. These measures reduce the chance that microbes will reach a wound, sterile tissue, medication, or laboratory culture.
Medical or clean asepsis aims to reduce microorganisms and limit their transmission. Surgical or sterile asepsis uses stricter controls intended to eliminate microorganisms from a field and its equipment. Autoclaves, disposable instruments, sterile fluids, and controlled handling are common tools in surgical asepsis.
Asepsis is often confused with antisepsis and sterilization. Antisepsis uses antimicrobial chemicals on living tissue, such as skin, whereas disinfection treats nonliving surfaces. Sterilization is a process that destroys or removes all forms of microbial life from an object. Asepsis is the broader condition or strategy of preventing contamination; it does not mean that every environment is permanently sterile.