Types of Centrifuge and Rotors with Principles and Uses


A centrifuge is a device that uses the principle of centrifugal force to separate the components of a mixture based on their density, size, shape, or viscosity. Centrifugal force is the apparent force that acts on an object moving in a circular path and pushes it away from the center of rotation. By spinning a mixture at high speed, a centrifuge can create a force that is much greater than gravity and cause the heavier or denser components to move towards the outer edge of the container, while the lighter or less dense components remain near the center. This process is called centrifugation and it can be used for various purposes in different fields of science and technology.

Centrifuges are widely used in laboratories for the analysis and purification of biological samples, such as blood, urine, DNA, proteins, viruses, bacteria, and cell organelles. Centrifugation can help to isolate specific molecules or cells from a complex mixture or to separate them based on their properties, such as size, shape, charge, or affinity. For example, centrifugation can be used to separate red blood cells from plasma, to extract DNA from cells, to purify proteins from a solution, or to isolate viruses from a culture.

Centrifuges are also used in industrial applications for the processing and separation of materials, such as food, beverages, chemicals, pharmaceuticals, metals, minerals, and fuels. Centrifugation can help to remove impurities or contaminants from a product, to concentrate or dry a substance, to separate solid-liquid or liquid-liquid mixtures, or to enrich or deplete certain components. For example, centrifugation can be used to separate cream from milk, to extract oil from seeds or nuts, to remove water from ethanol, to separate uranium isotopes for nuclear fuel, or to recover precious metals from ores.

Centrifuges vary in their design and functionality depending on their intended use and the type of mixture they are meant to separate. Some common features of centrifuges are:

  • A rotor: This is the part that holds the containers with the samples and spins them at high speed. The rotor can have different shapes and sizes depending on the type and number of containers it can accommodate.
  • A motor: This is the part that provides power to spin the rotor. The motor can have different speeds and modes of operation depending on the desired level of centrifugal force.
  • A temperature control unit: This is the part that regulates the temperature inside the centrifuge. The temperature control unit can have different settings and functions depending on the sensitivity and stability of the samples.
  • A control panel: This is the part that allows the user to set and monitor the parameters of the centrifugation process. The control panel can have different features and options depending on the complexity and automation of the centrifuge.

In this article, we will discuss some of the most common types of centrifuges and rotors used in laboratories and industries and their principles and uses. We will also explain how to calculate the relative centrifugal force (RCF), which is an important factor for determining the optimal conditions for centrifugation.