Final answer:
A tool free from all forms of microbial life has been sterilized. Sterilization is the process of destroying all microbes, whereas sanitization and disinfection may leave some microbes. Cleaning removes visible dirt and reduces microbial load, but without the high level of microbial death achieved by sterilization.
Step-by-step explanation:
If a tool is free from dirt, oil, and/or microbes, it has been sterilized. Sterilization refers to the complete elimination of all forms of microbial life, including bacteria, viruses, fungi, and spores. Tools or instruments subjected to sterilization are rendered safe for use in sterile environments, such as surgical rooms or in laboratory settings where any microbial contamination could severely compromise experimental results or patient health. In the context of a laboratory, items like pipettes, culture tubes, and metal inoculating instruments would be sterilized, often using methods like autoclaving, which subjects them to high heat and pressure to ensure all potential contaminants are destroyed.
Sanitization, on the other hand, reduces the number of microbes to safe levels but may not eliminate all pathogens. Disinfection kills many microbes but may not have the efficacy to destroy hardier forms like spores. A mere cleaning process would involve only the removal of visible dirt and some microbes, without ensuring a high level of microbial death.