A test tube is a piece of laboratory glassware. Simply put, a cone for conducting various studies in medicine. Designed to hold biological materials or samples. Test tubes are used, for example: for taking blood, urine, feces for analysis, testing water, vegetables, fruits, etc. The test tube can be made of various materials and have different shapes. For example, centrifuge tubes, thin-walled tubes, tubes with a rubber bottom, conical and cylindrical tubes and even tubes without a bottom, as well as tubes for gas research, vacuum tubes. The laboratory can also use special large-volume test tubes for laboratory animals, such as pigs or monkeys. They are plastic bowls that can hold