It is important to avoid digging into agar with the loop due to the high risk of cross contamination between different specimens. Contamination renders a petri dish or streak plate unusable. The American Society for Microbiology states that improper loop sterilization also increases the risk of contamination.Continue Reading
According to Boston University, modern streak plate protocol calls for three or four samples per petri dish. Each segment requires a new swab or sterilized loop. The most popular tools used to inoculate agar are cotton swabs and metal loops. Cotton swabs are single-use instruments because they do not withstand flame sterilization. Reusable metal loops require sterilization after every use.
Some scientists prefer to use plastic loops. These resemble metal loops but must be thrown away after each inoculation. Metal needles are another option. Like metal loops, needles require sterilization.
The American Society for Microbiology recommends sterilizing metal loops and needles by passing them through the flame of a Bunsen burner turned to its lowest setting. To sterilize an instrument, insert it into the light blue portion of the flame and hold it there until it glows orange or red. Gradually inserting the loop or needle into the flame prevents sputtering of potentially biohazardous liquids.
Another effective way to sterilize metal loops and needles is to place them in an incineration machine designed for that purpose. This method of sterilization takes less than 10 seconds. However, the incinerator takes several minutes to reach operating temperature.Learn more about Chem Lab
McDonald's does not certify any of its menu items as gluten free due to the possibility of cross contamination with gluten products in the kitchen. It recommends that customers with gluten sensitivities discuss the menu with their doctors to determine whether any items are safe for their particular dietary needs.Full Answer >
Makeup can go bad due to age and cross contamination with the skin. Old makeup can carry a range of bacteria that cause eye and skin infections.Full Answer >
Possible safety meeting topics include common sense safety, cold storage safety, cross contamination, food handling and office safety, according to State Fund. Specific safety meeting topics depend on the industry.Full Answer >
ISO/IEC 17025 is the standard that governs testing and calibration laboratories around the world. It outlines the general requirements that establish the competence of laboratories that conduct testing and calibration activities, including sampling.Full Answer >