subject: Different Types Of Available Laboratory Tube [print this page] If you ever had a science teacher then you are already familiar with at least one type of that most basic piece of laboratory equipment, the laboratory tube.
The tube that you did school experiments in was most likely a test tube made of glass and of a standard 18x150mm in size but laboratory tubes come in many different shapes and sizes and they can be made in a variety of materials.
Polystyrene plastic tubes have the same transparency as glass but they are not as heat resistant nor as resistant to chemicals and they cannot be sterilized in an autoclave. They are however less breakable and more cost effective. Made of a laboratory grade polymer they are sufficient for many basic lab tests.
An even more durable choice than polystyrene is polypropylene plastic; this produces laboratory tubes that are extremely durable and safe for dishwasher or autoclave. The only disadvantage is that tubes made of polypropylene are not as transparent as either glass or polystyrene.
Pyrex glass test tubes use borosilicate glass which is a strong glass with refractory properties which make it more resistant to thermal shock than other types of glass. It is less prone to leaching contaminants than lime-soda glass and it does not warp appreciably under high temperatures.
Test tubes made out of quartz glass are stable in hot temperatures and have a high visibility under the ultraviolet region of the electromagnetic spectrum.
The humble test tube comes in many shapes and sizes and can be sheer-sided or have a small rim or lip. There are several distinct types of laboratory tube.
Ignition Tubes are typically used to heat small quantities of liquids or other substances over a Bunsen burner. The process may result in charring the well of these slender tubes which can be difficult to clean so in a lab environment these are often disposable.
Boiling tubes are about half as big again as standard test tubes. They are generally made of pyrex to withstand high temperatures. Although they can serve as regular tubes they are made to a bigger size because normal test tubes are too narrow to safely allow the escape of gas bubbles from a briskly boiling liquid.
Centrifuge tubes can be made out of glass or plastic and are designed for use in centrifuge machine.
Thiele tubes have a distinct closed triangular shape and are commonly used to test the melting point of a substance in a manually-heated oil bath. This function is more efficiently performed today by a scientific instrument called a Melting Point Apparatus.
Laboratory tubes fulfil a multitude of functions from the heating, mixing and analysis of chemicals and substances to the collection and storing of samples. In a biology setting they are used for culturing moulds and bacteria or sprouting seedlings and you will find them being used in forensics labs for collecting blood, tissue or other samples. In a medical lab many diagnoses start with the analysing of blood or bodily fluid that has been extracted and injected into a test tube.
