In the right circumstances, pressure cookers can be used as an alternative for autoclaves, especially where minor processes are involved such as beauty and food production processes like brewing beer and not medical ones. Unlike the other brands tested, the Instant Pot was capable of inactivating 106 G. stearothermophilus spores, which indicates that it can sterilize items to the level generally deemed acceptable for laboratory autoclaves. If you do not use the lid, the pressure cooker will function like regular pot. Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon, United States of America, Roles Each metal implement was dipped in soil water to coat it in microbes and then prepared in two ways: 1) wrapped in at least two layers of aluminum foil, and stood upright in a beaker for sterilization, and 2) placed into sterile 25 mm x 150 mm culture tubes and stood upright in a culture tube racks for sterilization. Laboratory science requires careful maintenance of sterile reagents and tools as well as the sterilization of waste prior to disposal. Pressure cookers are used for cooking and although they create the perfect environment for killing certain bacteria, they do not kill all types of bacteria. The autoclave is considered a more effective method of sterilization as it is based on moist heat sterilization. The use of autoclaves as sterilization devices is ubiquitous across laboratories and medical facilities because of the short time required for sterilization, the ease of training and use of the equipment, the absence of harmful chemicals, and the consistent reproducibility as a means of pathogen control [3]. These data indicated that the Instant Pot pressure cooker could sterilize spores to the level of an autoclave, and we infer that it would be capable of inactivating all other less heat resistant organisms to properly sterilize laboratory items for research. here. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The strainer is located on the bottom of the chamber near the door. All four pressure cookers were able to sterilize these starting materials as well as a range of microbial types, including Gram-positive bacteria, Gram-negative bacteria, filamentous fungi, unicellular fungi, and mixed environmental samples. To create this article, 26 people, some anonymous, worked to edit and improve it over time. In new pressure cookers there are marks on the valve stem that indicate the pressure inside the cooker. This second definition is likely more accurate when considering the level of sterility achieved in most laboratory or medical situations because it may not be possible to verify that every contaminant is inactivated, but observing outgrowth, or lack thereof, is usually possible. Basic Food Microbiology. The valve has a thin layer of rubber that bursts itself to release the pressure and to avoid the danger of explosion. As the soil water left on the items touched the culture tubes, and they were occasionally manipulated outside of the hood, we infer that the culture tubes were also sterilized in these trials because no growth was evident following incubation with growth medium. Image Source: Microbe Online. All bacterial and fungal strains used in this study are listed in Table 1. Formal analysis, Methodology, Thanks to all authors for creating a page that has been read 900,380 times. Conceptualization, What exactly is an autoclave and how does it work? The CFU/mL was determined by preparing an identical dilution series to that created above, and plating on both nutrient agar (NA) and Sabouraud dextrose agar (SDA) to account for the presence of bacteria and fungi in the mixture. Introduction A pressure cooker, pressure steam steriliser or an autoclave is commonly used in the. should be placed in the autoclave so that steam can easily penetrate them. Project administration, Yes The size of the pressure chamber ranges from 100 L to 3000 L. The next important component of an autoclave is the lid or door of the autoclave. No, Is the Subject Area "Glucose" applicable to this article? Sterilization for 45 mins was necessary to inactivate the microbes in the soil water, which included 3 x 104 CFU/mL on NA and 3.7 x 103 CFU/mL on SDA, such that no growth was observed on either NA or SDA plates following one week of growth. Avoid touching the inner chamber surfaces. All Our Boilers are provided with Overseas Engineering Service And One Year Warranty. This article has been viewed 900,380 times. Once the pressure is reached, the whistle blows to remove excess pressure from the chamber. This may manifest as the maintenance of axenic strains for study and storage, the preparation of surgical devices, the growth of large cultures for compound extraction and purification, among others. By using our site, you agree to our. Phylogenetic analysis was performed using the Maximum Likelihood method and the generalized time-reversible (GTR) algorithm with 1000 bootstrap replicates in MEGA7 [19, 20]. Writing – review & editing, Current address: Department of Biology, Southern Oregon University, Ashland, Oregon, United States of America. Bowman Gray Center for Medical Education, Wake Forest University, Winston-Salem, North Carolina, United States of America, Roles Department of Biology, Southern Oregon University, Oregon, Ashland, United States of America, Roles Can I use a pressure cooker without a lid? However, steam autoclaves typically used for this purpose may not be readily accessible to everyone in the scientific community, such as K-12 teachers, researchers in the field, students in under-funded laboratories, or persons in the developing world who lack funding and resources. Resources, Autoclave Working Operation: Place containers in the autoclave. The autoclaves used in healthcare laboratories have an outer jacket that is filled with steam to reduce the time taken to reach the sterilization temperature. wikiHow is a “wiki,” similar to Wikipedia, which means that many of our articles are co-written by multiple authors. Yes Do You Remove Skin From Ham Hock? Incorporating a laboratory isolate into the analysis provided a realistic condition that researchers could encounter; the disposal of a culture derived from an environmental isolate. Yes No, Is the Subject Area "Medical devices and equipment" applicable to this article? This is the common type of autoclave used in laboratories. The lid is fastened by screw clamps and rendered airtight by an asbestos washer. Pressure cookers are not designed to reach the same temperatures as autoclaves that are needed for complete sterilization to occur. There's still a little bit of a learning curve, though, so if you're using a pressure cooker for the first time, it's important to know how to get started safely. What is causing my green beans to be a little cloudy after pressure cooking them? Benjamin Cumings Inc. California. A serious example of user error in sterilization was described by Dancer et al; an outbreak of surgical site infections in orthopaedic patients and endophthalmitis in ophthalmology patients occurred in sequence despite having relatively little overlap in specialty surgical instruments used by the two departments [7]. A whistle is present on the lid of the autoclave is the same as that of the pressure cooker. If the unit develops steam that escapes only from the proper point, then that is a good sign. Alternative methods for the sterile preparation of items is immediately necessary to democratize science and medicine, which could allow those under financial constraint improved access to sterilization techniques. Autoclave Temperature and Pressure: Autoclave uses dry saturated steam under elevated pressure and temperature to ensure potent microbicidal activity. With the help of steam alongside high pressure, autoclaves maintain a temperature that is considered too high for any virus, fungi, parasite or bacteria to grow or survive in. Older models could be opened at full-pressure and practically explode with their contents. Check the strainer to see if it is clogged. With the surge in use of these redesigned pressure cookers in the public sector, the low price, and the ready availability, we sought to determine whether modern pressure cookers could properly sterilize items common to microbiology and other biological sciences.