Basic Information on Test Tubes

发布时间：2021-11-09

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　　Test tubes come in various types, including standard test tubes, conical test tubes, and centrifuge tubes. [1] The dimensions of standard test tubes are specified as outer diameter (mm) × length (mm), such as 15×150, 18×180, and 20×200. Centrifuge tubes are designated by their capacity in milliliters.

　　Material: Glass

　　Style

　　(1) A straight‑mouth test tube is a round‑bottomed glass tube with a smooth, polished mouth. Its straight opening facilitates sterilization, effectively eliminating bacteria at the tube’s rim.

　　(2) A rolled‑edge test tube is a round‑bottomed glass tube with a rolled (or rounded) rim at the opening. The rolled edge (or rounded rim) enhances mechanical strength and facilitates secure clamping, preventing the tube from slipping off.

　　(3) The fermentation test tube is a short, narrow‑bore tube with a flat mouth and a round bottom; its inner diameter is 6 mm and its length is 30 mm.

　　(4) A side‑arm test tube is a straight‑mouth test tube equipped with a lateral branch. Its side arm is primarily used to connect to an air‑evacuation line, and the opening is fitted with a perforated rubber stopper that holds a filtration funnel, serving as a substitute for a microfiltration flask and functioning as the receiving vessel for microfiltration. A graduated test tube has a round mouth and bears volume‑scale markings on its body, allowing direct reading of measured volumes and offering convenient use.