Using weighing paper to measure solids
Using weighing paper to measure solids
To preserve a sample for culture and sensitivity testing, it should be collected aseptically in a sterile container. The sample should be kept at the appropriate temperature and delivered to the lab promptly to prevent overgrowth of contaminating organisms. It is important to follow specific guidelines provided by the laboratory for proper preservation and transportation of the sample.
Disposable gloves keep you from catching disease or contaminating a sample.
Natural niobium is not radioactive.
The gel barrier in a serum separator tube acts as a physical barrier between the serum and the clot after centrifugation. It helps to prevent the cells and clotting factors from contaminating the serum, allowing for cleaner sample separation.
Yes, I can provide sample letters of recommendation for high school students.
Keeping the crucible covered will keep dust from falling into it, which could offset the mass of both the crucible itself as well as the substance inside it. A covered crucible will also prevent material inside the crucible being lost to the air.
A cover slip helps preserve the environment you are observing. It also helps maintain a clean environment for the microscope lens and prevent samples from contaminating the lens, and perhaps contaminating the next sample. So, if you are looking at water, the cover slip will flatten out the bubble of water and trap it there for an extended period of time. At high magnification, you may add a drop of oil between the glass and the lens. The cover slip would prevent the oil (or water) from interacting with your sample, and will keep it clean. A cover slip isn't vital though. Sometimes one wishes to interact with the sample while under microscope. For example using a microscope to stick micro-pipettes into living neural tissue on a slide.
Sample, example.
because the sample didn't change color. Negative sugar/IKI test. No change from original blue bright color.
because the sample didn't change color. Negative sugar/IKI test. No change from original blue bright color.
Contaminating the outside of the sample container can introduce external substances that may interfere with the analysis or lead to inaccurate results. It can also compromise the integrity of the sample or cause cross-contamination with other samples. Maintaining a clean exterior of the container ensures the purity and reliability of the sample being tested.