Steam Sterilization

What is the main purpose of an autoclave?

To sterilize surgical and dental instruments, microbiological media, infectious waste, and other materials not harmed by moisture or heat.

What temperature range is typically set in microbiology laboratories for sterilization using an autoclave?

Between 121°C and 127°C (250°F and 260°F).

What is the minimum time required for sterilization at optimum temperature in an autoclave?

At least 15 minutes.

Why must sterilizers be regularly checked for operating effectiveness?

To maintain laboratory safety and comply with laws regarding infectious waste disposal.

What does a biological indicator contain that makes it useful for testing autoclaves?

Bacterial endospores.

What is the characteristic of bacterial endospores that makes them useful in sterilization testing?

They are highly resistant to both chemical and physical means of control.

What happens during the incubation phase of the biological indicator test after autoclaving?

If the endospores have been killed, there will be no growth; if not, they will germinate and ferment the substrate, causing a color change.

What indicates that sterilization is complete in an autoclave when using a biological indicator?

No color change during incubation signifies that the endospores have been killed.

What is the role of the special device used after autoclaving in the biological indicator process?

To crush the ampule containing fermentation broth without damaging the plastic vial so that the broth can contact the bacterial endospores.

Name two genera of heat-resistant organisms mentioned in the lecture.

Bacillus and Clostridium.