Autoclave Basics: What Every Life Scientist Needs to Know PART1

Autoclave Basics: What Every Life Scientist Needs to Know PART1

If you work in a life science lab, chances are you’ve used an autoclave. Autoclaves are pressure chambers that are used for the sterilization of waste, glassware, instruments, media, etc., so a basic understanding of how they work and how to use them is imperative to both avoid contamination in your experiments and to ensure safety of lab members and the community.

Biohazard waste

Firstly, let’s talk about biohazard waste—the kind that goes in the red trash bags. Biohazard waste includes any items that could be infectious, such as pipettes, petri dishes, gloves, or other materials that may have been contaminated by body fluids or bacteria. As biohazard waste eventually ends up in a landfill outside the lab, it needs to be sterilized to prevent outbreaks of infectious bacteria into the community. You should always be aware of your institution’s policy concerning red bag waste. Sometimes they’ll require you to autoclave it yourself, and sometimes they’ll have it taken by waste management personnel who manage the sterilization themselves. If you autoclave the waste, be sure to look up your state and institution regulations regarding the temperature, pressure, and length of the sterilization cycle for your load.

How do autoclaves work?

The first thing the autoclave does in a cycle is remove all trapped air from the chamber, as steam is a far more effective medium to achieve sterility than air. There are different types of autoclaves, some that use gravity to remove trapped air and others that use vacuum pumps. The vacuum pump method is more effective, especially if the material to be sterilized is porous with plenty of spaces where air can get trapped. Once the air is gone, the autoclave fills with steam until it reaches the target temperature and pressure. It will then automatically carry out the designated cycle. When the cool-down phase begins, the autoclave will maintain the pressure until it reaches a safe temperature so that liquids will not boil over inside the autoclave.

Which autoclave is right for you?

Autoclaves come in many sizes, from small bench-top models to larger machines that take up significant floor space. Additionally, the autoclave may be purchased for single-lab use or for multiple labs to share.

“Finding the appropriate autoclave starts with the size and quantity of one's load. From there, end users must determine the available space in their lab along with available utilities,” says Mark Wang, product supervisor of marketing at BIOBASE. “At BIOBASE, we specialize in top-loading autoclaves that occupy minimal floor space and do not require an outside steam generator or plumbing, thereby eliminating costly setup charges. Only water and an electrical outlet are needed to begin operation. We offer 14 self-contained models ranging from 25 to 110 liters, including two models with drying.”