glass tube closed at one end

a glass tube with one open end

a kind of laboratoryglassware , composed of a fingerlike length of glass tubing, open at the top, usuallywith a rounded lip at the top, and a rounded 'U' shaped bottom

a plain or lipped tube usually of thin glass closed at one end and used especially in chemistry and biology

Tube in which cells, tissues, etc., can be cultured.

A test tube, also known as a culture tube, is a piece of laboratory glassware composed of a finger-like length of glass tubing, open at the top, with a rounded U-shaped bottom. Often, the top features a flared lip. This is to aid pouring of a liquid from the test tube to a beaker.