What is Test tube?
[[File:Test tube true C.png|thumb|A typical test tube is long and narrow, with a curved base and flared top.]] A '''test tube''' is a kind of [[laboratory glassware]], composed of a fingerlike length of [[glass]] tubing, open at the top, usually with a rounded [[lip]] at the top, and a rounded 'U' shaped bottom. They range in size from a couple [[inch]]es to several inches long, from a few [[millimeter]]s to a couple [[centimeter]]s in [[diameter]]. They are designed to allow easy heating of [[sample]]s, to be held in a [[flame]], and often are made of expansion-resistant glasses, such as [[borosilicate glass]] (known by brand-names such as Pyrex and Kimax). Tests tubes are often preferred above [[beaker]]s when multiple small chemical or biological samples have to be handled and/or stored. [[Vacutainer]]s are a type of test tube that can be used for both collection and storage of blood. {{LaboratoryEquipment}} [[Category:Laboratory equipment]] {{sci-stub}}