Content Curator
Centrifugation is the process of separating dissolved particles from its solution on the basis of its shape, size, density or viscosity of the medium with the usage of centrifugal force. The centrifugal force i.e., the outward force is applied when the solution is spun at a high speed in the rotor which makes the lighter substance stay on the surface while the heavier substance settles down in the bottom of the tube. Centrifugation proves to be efficient in separating substances when ordinary filtration processes fail to give the desired results.
What is Centrifugation?
Centrifugation is a process in which the centrifugal force is applied to separate particles from a solution on the basis of their density, size, shape and viscosity of the medium. Centrifugation is an important separation technique that is based on the concept of centrifugal force and finds application in various branches of science.
Centrifugation
Applications of Centrifugation in Industry
- Miscible liquids can be separated from each other with the help of centrifugation.
- RBCs, WBCs, and plasma of the blood can be separated from each other.
- Centrifugation is employed to separate blood cells and mineral crystals present in urine.
- In the production of bulk drugs, crystalline drugs can be separated from the liquor.
- Mammalian cells can be purified.
- Hydrodynamic properties of macromolecules can be examined with the help of centrifugation.
- This process is also used to separate drugs present in blood, urine and tissue fluids.
- Centrifugation is employed in the fractionalization of many subcellular organelles.
- Purification of wine and beer is made economical with the centrifugation technique.
- Pure form of insulin can be obtained with the usage of a special type of centrifugation called ultracentrifugation.
- Ultracentrifugation is also used in the separation of virus particles that are utilized in industrial applications.
- Isotopes of uranium (U-235 and U-238) can be separated from each other with the use of a uranium centrifuge.
Industrial Centrifuge
Applications of Centrifugation in Daily Life
Centrifugation not only has its applications in the industries and laboratories but also in everyday life. Some examples for the same are listed down below:
- When a ball is kept on a surface with a closed container on top of it that is spun at a high speed, the ball moves at the rim of that container.
- In a washing machine, the clothes are spun which results in the water being squeezed out of the clothes.
- When curd is churned, butter goes to the sides of the container.
- When vehicles take a sudden turn, the passengers move towards the outer edge of the vehicle because of centrifugation.
- Salad spinner uses centrifugation to remove excess water from the salad.
- Chalk powder and water can be segregated with the use of centrifugation.
- In a merry-go-round, people experience an outward force because of centrifugation.
- A stunt person circles around in the well of death without falling off because of centrifugation.
Things to Remember
- Centrifugation is one of the most frequently applied techniques in the medical as well as research sectors since it helps professionals achieve fast results while also cutting down the cost of conducting otherwise-expensive experiments, making it an integral part of a diverse range of experiments.
- Centrifugation was first introduced by Antonin Prandtl in 1864 when the technique was used in the dairy industry for bulk separation of milk and cream. Later on, Friedrich Miescher, a Swiss physician and biologist, first applied the technique in the lab.
- The application of centrifugation is not just limited to labs and industries. Human centrifuges are used for multiple training purposes wherein astronauts and pilots are made to experience high amounts of forces. Their reactions and tolerance levels are tested and made better with this technique.
Sample Questions
Ques. How does centrifugation separate the particles on the basis of their densities? (1 Mark)
Ans. When the mixture is rotated at a high speed, centrifugation causes the particles with higher density to settle at the bottom and the ones with lower density to rise to the top.
Ques. What principle does centrifugation work on? (1 Mark)
Ans. Centrifugation works on the principle of sedimentation. Due to the acceleration produced by the centrifugal force, the denser particles sediment down while the lighter particles rise up.
Ques. Can centrifugation break chemical bonds in a suspension? (1 Mark)
Ans. As mentioned above, the centrifugation process works on the principle of sedimentation and can separate two different types of particles with different physical properties but cannot break any chemical bond.
Ques. What are the different types of centrifuges that exist? (2 Marks)
Ans. The different types of centrifuges are:
- Low-speed centrifuge: It maintains 4000 - 5000 rotations per minute.
- High-speed centrifuge: It maintains 15000 - 20000 rotations per minute.
- Ultracentrifuge: It maintains about 65000 rotations per minute.
Ques. What are the disadvantages of centrifugation? (2 Marks)
Ans.
- Centrifugation is unsuitable for conditions with high compression or limited pressure.
- The process is sensitive to changes in gas compression.
- During the application of centrifugation on samples, the cells are exposed to high amounts of forces that can lead to alterations in its structure.
Ques. Explain centrifugal forces and its characteristics. (3 Marks)
Ans.
- Centrifugal forces are the forces that arise when a substance is rotated at high speeds.
- These forces tend to push the substance outwards and are directed perpendicular to the axis of rotation.
- This force is considered to be an imaginary force as it exists only because of the inertia of the rotating object.
- The magnitude of this force can be calculated with the formula:
F = ω2r
Ques. Does centrifugation work when the difference in the densities of the solute and solvent is negligible? (2 Marks)
Ans. In case the densities of the solute and solvent are similar, the two will not be separated with each other and will stay suspended in the solution, rendering the technique ineffective in such conditions. It is so because centrifugation helps the particles with higher density to sediment down and the one with lower density to rise. In this particular case, since there is no difference, the desired outcome won’t be attained.
Ques. While operating a centrifuge, what are the points that should be kept in mind? (3 Marks)
Ans.
- The centrifuge should be placed carefully while ensuring that it has a stable and firm support.
- Proper checks for cracks on the bottles and containers to be used should be done before the conduction of experiments.
- The speed of centrifugation should be maintained and regulated properly.
- The validity of all apparatus should be checked before usage in the experiment.
Ques. What is the difference between centrifugation and filtration? (3 Marks)
Ans.
Centrifugation | Filtration |
---|---|
Centrifugation is used to separate particles that are very small in size. | Filtration is used to separate particles that are relatively larger in size. |
It deploys a rotatory machine which is called a centrifuge. | It deploys the usage of filtration apparatus such as paper/filter screens. |
It makes use of centrifugal forces. | It does not make use of centrifugal forces. |
Comments