Microbiology Lab Safety and Sterilization Methods

What is the maximum time required for sterilization by dry heat at $150^ ext{°}C$?

Which microorganisms are considered harmless and classified as Class I?

At what temperature range do most vegetative bacteria get killed during steam sterilization?

What is the minimum temperature and time for autoclaving to be effective?

What is the purpose of using cotton wool and aluminum foil in the sterilization process?

What does Tyndallization involve in its sterilization process?

What type of microorganisms is classified as opportunistic pathogens?

When autoclaving, what is the purpose of removing air from the chamber?

Microbiology Lab Safety

Basic rules apply to chemical labs, including GHS hazard pictograms and H/P statements
Additional safety precautions needed for infectious agents, such as Ebola and Sars-CoV-2, are important
Some microorganisms considered harmless, such as Lactobacillus and Bacillus subtilis
Other microbes are potentially harmful, including opportunistic pathogens like Serratia marcescens, certain coliform bacteria, or Staphylococcus aureus.
Some microorganisms can affect animals or plants

Sterilization Methods

Sterilization methods depend on the material and time required
Dry heat sterilization is used for glass and metal, typically at 180°C for 30 minutes or 150°C for 3 hours (for items wrapped in cotton wool).
Steam sterilization kills most vegetative bacteria at 60-70°C, but spores can resist up to 120°C depending on exposure time
Tyndallization involves heating material 3 times to 100°C for at least 8 hours
Autoclaving uses saturated steam and pressure (at least 1 atmosphere) to sterilize material at 121°C for 20 minutes.
Faster autoclaving methods exist at higher temperature, like 134°C for 6 minutes for medical applications, but this method requires the container to be filled at most 3/4 of the way.
Materials and labels need to be waterproof

This quiz covers essential safety protocols in microbiology labs, including the proper handling of hazardous chemicals and infectious agents. It also explores various sterilization methods applicable to different materials and organisms. Test your knowledge on these crucial topics to ensure laboratory safety and efficiency.