Updated on 19 October, 2021
A test tube, also called a centrifuge tube or culture tube, is an invaluable piece of medical glassware - often used in surgical laboratories - made up of a narrow tube of translucent (or partly translucent) medical glass, open at both the top and bottom and containing a collection cup at one end. It may be made of different glass material but the most common type is made from polyvinyl chloride (PVC), coloured to make it easier to see through and sealed at both the top and bottom to prevent contamination. The tubes come in different diameters to suit different purposes. Thus, for example, the medical centrifuges are usually smaller than those used in hospitals while the medical samples may be larger in diameter.
Many people use test tubes without even knowing it. They are so common that we often don't consider them when filling syringes or writing down measurements on paper. But they are very important in the laboratory. They allow the researcher to observe the physical properties of the sample, particularly the response of its chemical constituents during collection and analysis. Without these tubes, it would be very difficult to study even small quantities of materials under laboratory conditions, let alone culture very small quantities of living organisms.
Most test tubes are designed with some mechanism for restricting the flow of fluid inside the tubes. There are two main types of test tubes: mechanical and biological. Mechanical test tubes, also called centrifuges, are usually made out of plastic or other nonporous materials and can be used for all practical applications. These test tubes contain a large opening through which the fluid flows and is kept in a fixed position for the duration of the study.
Biological test tubes, on the other hand, are much smaller than mechanical ones and are commonly made out of biology paper. They have one large opening through which the fluid flows and is held at a definite position for the duration of the study. Because of their size, these tubes are used for single cell or tissue culture processes only. If you wish to collect multicellular organisms (or vacteria and fungi), you will need a larger type of testing tube called a dynamic test tube. It is larger and requires special racks (called growth chambers) to house the cultures for a sufficient period of time.
There are several different kinds of test tubes. The most common type of test tubes is the Bunsen burner test tube. This is an externally-visible tube having three different flues - two inside the tube and one outside it. The outside portion of the tube is filled with a solution (usually sodium hydroxide) that can burn and kill bacteria if it comes into contact with the fluid inside. There are also disposable tubes that can be reused after use.
When it comes to the culture tubes, there are both closed and open types. Closed culture tubes have solid ends while open culture tubes have open, hollow surfaces. These culture tubes are used in the same way as Bunsen burner test tubes. However, they have their own special needs because they cannot be reused. You can either sterilize them by putting them in a autoclave machine or heat them before use.
Another important difference between the two is that the test tubes used in medical laboratories usually have to undergo a number of tests to check the properties of the sample and make sure that everything is healthy. The test tubes in the automotive industry, on the other hand, have to be recharged regularly so that they do not lose their power to kill bacteria. And the ignition tube must be replaced from time to time because of its small size. The reason for this is that it is very easy to break the ignition tube in the test tube when in use.
Finally, when you think of all the complicated techniques used in test tubes and centrifuges, you may find it hard to believe that ordinary people actually use them. All these things were invented for one reason - to simplify complex chemical solutions. If you have an interest in knowing more about these devices, you should look up some information about chemical solutions, centrifuge tubes, and other equipment that are used in various industries.