There are a variety of options for cleaning laboratory products. First, determine what level of cleanliness is needed. Sometimes just soil, grease, or proteins need to be removed. Laboratory cleaning products, ultrasonic cleaners and laboratory dishwashers can all be used for this level of cleaning. Other processes may require sterilization to kill all microorganisms, which can be done using autoclaves.
Laboratory Cleaning Products
Laboratory cleaning agents are specially made for manual cleaning as well as in the machine washers that laboratories typically use. They are formulated to clean specific residues commonly found on soiled or dirty labware. Formulations include dry powders that can be used with ultrasonic cleaners, liquid detergents intended for laboratory dishwashers, cleaners for trace metal analysis, cleaners for medical instruments, and protein removal cleaners for tissue, blood and body fluids.
Ultrasonic cleaners create sound waves that move through a solution in which the parts are immersed. Those sound waves create bubbles which rapidly form and collapse. When this happens against a soiled part, it loosens and removes the soil from the dirty part. Using the appropriate cleaning solutions for the part and soil type add to the effectiveness. Ultrasonic cleaners with heaters can be more efficient at cleaning parts and equipment. Because energy can build up during the ultrasonic process, flammables and solutions with low flash points should never be used in ultrasonic cleaners.
The advantages of using a laboratory washer over a consumer dishwasher are numerous; laboratory dishwashers are designed to eliminate cross contamination between wash and rinse cycles. They also wash at higher temperatures for better sanitation and faster cycles, which is important in a work environment. The interior design of a laboratory washer is set up to accommodate laboratory glassware. Accessories are available to hold items such as test tubes and petri dishes or pipets to maximize the space utilization and ensure the glassware remains safe during the washing cycle.
Autoclaves provide steam sterilization using a combination of temperature and pressure for a set time. A common autoclave cycle is 121ºC at 15 psig for 20 min.; however, settings on individual machines can vary slightly. While autoclaving does sterilize products, it does not “clean” products, so labware should be cleaned to remove any soil or debris first by using either a manual cleaner, ultrasonic cleaner or a laboratory washer. Because you cannot see whether a product has been sterilized just by looking at it, or be certain that the autoclave cycle was completed with no problems, there are products that allow testing of both the autoclave and the individual autoclave cycles.
Biological indicators can be put through an autoclave and then put into an incubator. If the autoclave is operating properly, no growth will appear after incubation.
Sterilization strips and tapes allow for testing with each cycle. The strips or tape change color after the cycle is run to indicate that the proper temperature was reached during the sterilization process.
Due to the high temperature required for autoclaving, there are some plastics that cannot be autoclaved because their maximum use temperature is below the temperature needed for autoclave sterilization. These would include polyethylene, polystyrene and polyurethane. It is important for anyone using high temperature sterilization processes to determine if their labware can tolerate high heat applications.
For more information on laboratory cleaning, read EZ Facts No. 360, Laboratory Cleaning.
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