Both of these centrifuges are capable of spinning a rotor

  • In general, applications for centrifugation specify the degree of acceleration that is to be applied to the sample rather than specifying a specific rotational speed such as revolutions per minute. This is because acceleration is more sensitive to changes in velocity than rotational speed. This is due to the fact that acceleration is more sensitive to changes in speed compared to rotational speed. The acceleration is most commonly expressed in terms of gravity multiplied by g (or multiples of g or g-force), where g is the standard acceleration value that is caused by gravity at the surface of the Earth (9.81 m/s2)The difference between revolutions per minute (rpm) and revolutions per second (rcf) is important because the acceleration that is produced by two rotors of different diameters rotating at the same speed (rpm) will be different.

    Both of these centrifuges are capable of spinning a rotor that contains 1.5/ 2 mL tubes at the same speed (14,000 rpm), but the acceleration that is applied to the samples is very different: 13,100 g as opposed to 20,817 g, which results in different outcomes. Some centrifuges have buttons directly on the control panel that allow for automatic conversion between rpm and rcf. These buttons can be found on some of the more advanced models. These buttons were developed to simplify day-to-day tasks while simultaneously enhancing the reliability of data reproduction. For the purpose of conversion, if your centrifuge does not have an rpm-rcf converter, you can either use a formula, the rpm-rcf converter that can be found on the homepages of suppliers of centrifuges, or a nomogram. All of these options are available to you. A parameter known as the k-factor can be utilized to provide an accurate description of the sedimentation distance in a test tube. When the rotational speed is increased to its maximum, this factor, which is also known as the clearing factor in some circles, represents the relative pelleting efficiency of a centrifugation system. In general, the value of the k-factor is used to estimate the amount of time, t (in hours), necessary for the complete sedimentation of a sample fraction that has a known sedimentation coefficient measured in s (svedberg). This estimation is made using the value of the k-factor. For the purpose of this estimation, the k-factor value will be used.

    How to pick the high speed centrifuge that's going to be the best fit for your particular application.


    If you are going to follow a particular protocol, you need to make sure that you use the same kind of rotor, that you apply the specified amount of relative centrifugal force (rcf), that you maintain the same temperature, and that you run for the same amount of time.


    • The two varieties of rotors, known as fixed-angle and swing-bucket rotors, are the types of rotors that are utilized in laboratory centrifugation the majority of the time

    • Only a small fraction of applications necessitate the use of specialized rotors, such as drum rotors, applications that require continuous flow, and others like them

    • Because the rotors that collect the precipitates have flow throughs, the precipitate collection process can be done in a continuous flow

    • These systems are utilized in the process of harvesting fermenters in the food industry, as well as in the production of juice

    • Another application of these systems is in the pharmaceutical industry

    • It is essential to have specialized versions that are adapted to the application in question and optimized for use with it

    It is immediately obvious as a benefit of the rotor that it does not contain any moving parts, which is a feature that is immediately noticeable. This causes there to be less stress on the metal, which in turn causes there to be a longer lifespan for the component. Additionally, it makes it possible to achieve a higher maximum g-force, and for many applications, it makes it possible to realize faster centrifugation times. All of these benefits come as a result of the fact that it makes it possible to increase the maximum g-force. The only drawback associated with a rotor with a fixed angle is that it has a restricted capacity and, as a result, less adaptability. When the pellet is spinning, it can be found anywhere within the tube, from the side to the bottom, depending on the angle at which the tube is held; however, it is most likely to be found on the side of the tube. The majority of rotors have tubes that are angled at a 45-degree angle from one another. The pellet will become more dense if the angle at which the tubes are positioned is increased. A rotor with an angle that is not quite as acute will produce pellet areas that are more widely dispersed.

    This specific type of rotor provides a wide variety of adapter systems and a high sample capacity, both of which combine to make it exceptionally versatile for use with a variety of tube formats, including plates in the SBS format. It is also capable of handling a large number of samples. The metal of the rotor and the buckets are put under a greater amount of stress as a result of the moving parts of the swing bucket. This is because the weight of the buckets places a load on the two pivots and grooves, causing them to be stressed. Therefore, a swing-bucket rotor is restricted to a lower maximum g-force in comparison to a fixed-angle rotor, which results in longer centrifugation times. This is because of the difference in the two rotors' design. This is due to the fact that the maximum g-force is significantly lower. In accordance with the swing-bucket principle, the pellet is positioned in a horizontal orientation at the bottom of the tube (while the tube is in the process of operating). It is easier for the user to retrieve pellets that are located on the bottom of the tube as opposed to pellets that are located on the side of the tube.

    The majority of centrifuges can be divided into two distinct categories: floor-standing models and bench-top models.

    Floor-standing centrifuges require a minimum of one square meter of space on the laboratory floor. This is in spite of the fact that they free up bench space. They are a good choice for protocols that need either high speed or high capacity, both of which are common requirements. Ultracentrifuges, super-speed centrifuges, and low-speed centrifuges are the three variations of speed that are available for floor-standing centrifuges. One variety of high speed centrifuge is known as an ultracentrifuge, which is a machine that can reach extremely high speeds. These refrigerated centrifuges feature a chamber that is capable of being evacuated, which enables them to rotate at speeds of up to 150,000 revolutions per minute. The magnitude of the g-force is somewhere in the neighborhood of 300,000 to 1,000,000 g. It is imperative to make use of specialized vessels, which must either be housed within the rotor itself or be attached to a rotor that is specifically designed for this purpose. Super-speed floor-standing centrifuges are the laboratory apparatus that should be used whenever g-forces ranging between 40,000 and 60,000 g are required. Low-speed floor-standing devices are typically required to be utilized for applications requiring a maximum g-force of less than 10,000 rcf. Examples of such applications include those that deal with cell culture or blood.