By Brianna Baggett
Aseptic techniques are used in the medical field, research, and pharmaceutical studies in order to prevent contamination. In the lab setting, aseptic techniques involve procedures designed to prevent microbial contamination and ensure the validity of the experiments being performed. By creating and maintaining sterile conditions, researchers can study biological systems without the interference from unwanted microorganisms. The type of organisms being worked with will determine the different cleaning or sterilization procedures needed. Some microorganisms are more challenging to kill than others and require stronger chemicals or cleaning methods than other microorganisms. For example, fungal spores are very resilient to some disinfectants and may require sporicides.
The various aseptic techniques are methods that focus on preventing contamination while performing certain tasks. The use of sterile instruments, having controlled environments, wearing the proper lab attire, and careful handling practices are necessary to maintain a sterile environment. Going through the proper cleaning processes is essential for performing proper aseptic techniques. It is important to understand the differences between sanitizing, disinfecting, and sterilizing when working with aseptic techniques.
Sanitizing reduces the amount of microorganisms to a safer level; however, disinfecting is more effective at killing microorganisms, usually by the use of chemicals. Disinfecting surfaces with chemicals such as bleach, ethanol, and isopropyl alcohol is a common step when performing aseptic techniques. It helps with cleaning objects that aren’t able to go through certain sterilization processes. Sterilizing, on the other hand, is a process that eliminates all microorganisms. There are different ways in which sterilization can be achieved, which consist of steam, chemical, or dry heat. Steam sterilization is commonly done with the use of autoclaves by using high-pressure steam at specific temperatures. Chemicals are often used when objects are heat-sensitive, so this process can be done at lower temperatures. Dry sterilization is done for things that are sensitive to high moisture content. Properly sterilizing equipment before and after use can help minimize contamination.
Scientists working with bacterial or cell cultures must prevent contamination to ensure the validity of experimental results. Common practices include sterilizing work surfaces with disinfectants like 70% ethanol or isopropyl alcohol, using laminar flow hoods or biological safety cabinets to provide a sterile workspace, and using tools that are pre-sterilized or objects that can be flame-sterilized. Some scientists would work near a Bunsen burner when transferring bacterial cultures to create an updraft that prevents airborne microbes from settling on the sample. This can be used to aid in eliminating contamination to help prevent the research from being invalidated. Training and adhering to protocols are essential for implementing aseptic techniques. Standard operating procedures (SOPs) outline the steps that are necessary to follow when performing aseptic techniques. When these guidelines aren’t followed, that can lead to contaminating the sample and the researcher.
Although aseptic techniques can mitigate much of the contamination, human error and environmental factors are still ongoing concerns when performing aseptic experiments or procedures. Some human errors may consist of improper handwashing, failure to maintain a sterile environment, not wearing the proper lab attire, or sloppy lab techniques. While some environmental factors are inadequate ventilation, failing to validate or maintain necessary equipment. A few ways researchers and scientists can reduce these issues are through training, or they may need to reference back to SOPs.
Each laboratory may have a different way of implementing aseptic techniques. At Asymmetry Technologies, we ensure all instruments are sterilized before usage. Our Biological Safety Cabinet has a UV sterilization process that helps maintain sterilization when it’s not in use. Before using the Biological Safety Cabinet or laminar flow, they get sprayed and wiped out with either 10% bleach or 75% isopropyl alcohol. Then anything going in the cabinet or laminar flow gets sanitized with 10% bleach or 75% isopropyl alcohol. Objects that can be autoclaved are autoclaved at 121°C and 15 psi for around 15 min. Other objects, such as pipette tips or inoculation loops, have already been through the pre-sterilization process. Sterile gloves and lab coats are worn when handling different microorganisms or when working in either a laminar flow hood or a biological safety cabinet. When working with hazardous chemicals, safety goggles, lab coats, and sterile gloves are worn. Researchers are required to have experience in working with aseptic techniques and to go through extensive training to maintain a sterile working environment. It is necessary to go through all these precautions to ensure the validity of the experiments, reduce contamination, maintain a controlled environment, reduce contamination in samples, and maintain a safer work environment.
