Glass Test Tubes are a kind of Laboratory Glassware that commonly have round U-shape bottom, which open on the top. However, a flat bottom, a round bottom, or conical bottom test tubes are also available. Laboratory Test Tubes are available in various shapes and sizes, especially from 10 to 20 mm wide and 50 to 200 mm long. Customized solutions of test tubes are also provided by some manufacturers. Test Tubes are often used for holding, mixing, or heating relatively smaller quantity of liquid or solid chemicals for qualitative experiments. Shape of the test tube helps to minimize the mass loss while pouring thereby making easier to clean and monitor the content.