A Comprehensive Guide to Laboratory Centrifuges Including an Overview of Centrifugation and the Numerous Applications It

Alexander Prandtl invented the first centrifuge in 1875 with the intention of using the machine to separate cream from milk

Alexander Prandtl invented the first centrifuge in 1875 with the intention of using the machine to separate cream from milk. His invention was named after him. Since then, the laboratory floor centrifuge has developed into one of the essential tools for a wide variety of clinical and scientific procedures, and it has become increasingly more sophisticated as well.



What exactly is it that the centrifugation process entails?


  • Centrifugation is the process of using centrifugal forces to separate particles from a solution

  • This process is known as centrifugation

  • The effectiveness of the separation is determined by a number of factors, some of which are the size and shape of the particles, the density of the particles, the viscosity of the solution, and the speed at which the centrifugal rotor is spinning

The sample solution is shown in Figure 1 both before and after it has been centrifuged. The results of the centrifugation are shown.

The following is an explanation of the concept behind centrifugation:

The process that is known as centrifugation and the idea of centrifugal force are both utilized in the operation of the apparatus that is known as a centrifuge. When a body is made to rotate about a central axis, the resulting motion of the body results in the application of a radial force that acts in an outward direction. The sedimentation process is characterized by denser particles being thrown in a more rapid direction opposite to the direction in which the centrifugal pull is acting, and this centripetal force is utilized to speed up the sedimentation process. The centrifugal principle is put to use in a wide variety of applications in today's sophisticated laboratories. These applications are used to separate different components that are contained within samples.

The fundamental concept that underlies the centrifugal force is depicted here in Figure 2.

What Varieties of Centrifuges Are There for Customers to Select?

These variants cover a wide range of rotor speed, refrigeration conditions, and benchtop centrifuge size, and they are currently available for purchase on the market in a great number of different iterations. This article focuses primarily on discussing centrifuges that are typically found in research facilities and laboratories.

In a floor centrifuge that is used in a laboratory, liquid suspensions are typically rotated at a high speed by an electric motor that is driven by the benchtop centrifuge itself. As a result of the centrifugal force, the lighter particles move closer to the center of the sample tube, while the heavier particles move toward the outside of the sample tube. The sedimentation principle is what allows laboratory centrifuges to function properly; this principle makes use of the centrifugal force to differentiate between substances of higher and lower densities. Once the sample that is housed inside of a floor centrifuge tube has been subjected to centrifugation, the solid components of the sample will have a tendency to settle to the bottom of the tube. Because of the way that the tube is arranged inside of the centrifuge, the solids can be extracted from the mixture more quickly.

Figure-3: Centrifuge tube holder

The typical sample volume range for microcentrifuges is between 0.2 and 10.0 ml; however, certain centrifuges have the Eppendorf placing capacity. Microcentrifuges are designed to work with relatively small sample volumes. Because it is possible to use Eppendorf tubes with varying capacities, a microcentrifuge offers a greater degree of flexibility in terms of the volume of the sample that it is able to process.

Figure-4: Mini Centrifuge

For applications that require less space and are more condensed, a benchtop centrifuge would be the best choice to use in the laboratory. Not only does it have a smaller footprint, but it is also more compact. However, because they can only hold a limited quantity of the substance, they are most useful for applications that require a small sample size. This is because larger quantities of the substance would be difficult to contain. Although not always included, some benchtop centrifuges come equipped with their very own built-in refrigerators. However, this feature is not standard on all models. In the event that the sample goes through the thermal degradation, it is recommended that a refrigerated benchtop centrifuge be acquired. In general, benchtop centrifuges can be put to a wide variety of uses, such as the processing of samples that contain blood, DNA, RNA, protein research, tissue culturing, and cell culturing, to name a few of the more common applications.

Figure 5: A laboratory centrifuge (click here) that can be placed on a bench

Regular centrifuges are larger than laboratory centrifuges and are sometimes referred to as floor model centrifuges. The functions that are performed by regular centrifuges are identical to those that are performed by laboratory centrifuges; however, regular centrifuges are known to perform the same functions as laboratory centrifuges. These types of centrifuges require more space than benchtop centrifuges do, but they are able to handle larger sample sizes, and the tubes that they use can hold as much as 750 milliliters each. However, they are not as portable as benchtop centrifuges. There is a possibility that the floor centrifuges have a refrigeration function, and the temperature selection range that is available goes from -20 degrees Celsius to +40 degrees Celsius. Floor centrifuges are an indispensable piece of equipment for use in the processing of samples that may contain DNA, RNA, antibodies, viruses, or proteins.

The ultracentrifuges are the high capacity centrifuges; they have a Relative Centrifugal Force of up to 1,000,000 g and can spin at a maximum of 150,000 revolutions per minute. In terms of acceleration, these centrifuges are the high capacity centrifuges. There are two distinct types of ultracentrifuges, which can be categorized as preparative ultracentrifuges and analytical ultracentrifuges, respectively. In the process of isolating biological and organic components such as DNA, RNA, lipoproteins, membranes, organelles, and viruses, ultracentrifuges that were designed for preparative purposes are used. These ultracentrifuges are utilized in the process. Analytical ultracentrifuges are utilized in order to make an immediate determination as to the nature of the samples being tested. In addition to determining the shape and mass of molecules, they are also able to determine the equilibrium and velocity sedimentation of the molecules. In the field of nanotechnology, ultracentrifuges are versatile enough to serve a wide variety of purposes for a variety of applications.

Utilizations and Case Studies of the Centrifuge

Centrifuges are extremely versatile pieces of equipment that can be used for a wide range of different tasks in the laboratory. The following is a list of some of the more common purposes that centrifuges are put to use for:

The separation of mixtures that have densities that are relatively close to one another The separation of immiscible liquids

The process of sedimentation as well as the separation of solids that were suspended

The process of eliminating blood cells from the body Isolation and extraction of proteins

Isotope separation

Space travelers will experience artificial versions of Earth's gravity in their habitats.

Taking apart the various creams

The process of extracting DNA and isolating it from plasmids, typically using bacteria or yeast as the source.

The production of materials in an atmosphere characterized by a strong gravitational field. The spinning action of a washing machine 

Olateju Awosika

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