Test tubes are familiar items of glassware or plasticware found in most biological, chemical and clinical research laboratories, schools, universities, and other industrial workplaces. They are elongated, open-topped tubes with a closed base, made in a range of lengths and diameters, and typically held in special test tube racks designed to accommodate them. Test tubes also include boiling tubes, culture tubes, assay tubes and small ‘Durham’ tubes, ranging in capacity from a few mL up to 50mL or more.

Reusable borosilicate glass test tubes have high resistance to heat, thermal shock and chemicals, and are used for the most demanding applications. Soda lime glass test tubes are used for more general-purpose activities. Plastic test tubes are manufactured from polypropylene, or from polycarbonate and polystyrene for optical clarity. Some plastic test tubes are autoclavable, many are disposable.

What sort of test tubes are available?

• Thin-walled test tubes, medium-walled test tubes or thick-walled test tubes
• Round-bottom test tubes predominate, others have flat or conical bases
• Rimmed test tubes for easy pouring, or rimless test tubes
• Screw top test tubes, plain top test tubes or test tubes with ground glass sockets
• Test tubes with screw tops, stoppers or push-on caps
• Graduated test tubes

What are test tubes used for?

• Sample storage on the bench or in the refrigeratoror freezer
• Routine testing, clinical assays, photometry, chemical reactions
• Cell or microbial culture in solution or on agar slopes
• Some test tubes may be suitable for centrifugation
• Teaching and demonstration purposes in the classroom