Test tubes are used by chemists in the lab to heat, hold and mix small quantities of liquid or solid chemicals during experiments. They have a round bottom and are made of borosilicate glass to withstand temperature changes and resist the reaction of chemicals.
Test tubes have clear glass to allow monitoring and observation during an experiment. The straight sides and round bottom are designed to reduce mass loss when pouring and also make them easy to clean. A test tube with a stopper is used to store samples and for other storage purposes. Test tubes are brittle; thus they can easily break when they are not handled carefully.