Autoclave

Before a culture is set up, an autoclave uses hot, pressurised steam to sterilise the growth medium and suitable Petri dishes. Sterilising kills microorganisms already present. It gives the intended microorganism a clean starting place; it does not keep the dish sterile if it is left open afterwards.

An autoclave uses hot, pressurised steam to sterilise glassware and growth media; this can kill even resistant microbial spores. A glass inoculating loop can also be passed through a flame before transferring a culture, then allowed to cool before it touches the microorganisms. Flaming the neck of a culture bottle when it is opened reduces the chance of contamination at its opening.