Historical information
A test tube, also known as a culture tube or sample tube, is a common piece of laboratory glassware consisting of a finger-like length of glass or clear plastic tubing, open at the top, usually with a rounded U-shaped bottom. Test tubes are widely used by pharmacists to hold, mix, or heat small quantities of solid or liquid chemicals, especially for qualitative experiments and assays. Their round bottom and straight sides minimize mass loss when pouring, make them easier to clean, and allow convenient monitoring of the contents. The long, narrow neck slows down the spreading of vapours and gases to the environment. Test tubes are usually held in special-purpose racks. Culture tubes for biology are usually made of clear plastic (such as polystyrene or polypropylene) by injection moulding and are often discarded after use.
Physical description
A clear plastic test tube