Centrifugation is a technique that uses centrifugal force to separate components of a solution based on properties like density, size, and shape. It works by spinning the solution at high speeds, allowing heavier components to sediment to the bottom. There are two main types - density gradient centrifugation, where particles separate through a density gradient, and differential centrifugation, which separates organelles from cells. Centrifugation has many applications, including separating cream from milk, clarifying wine, and purifying proteins and cells.

1. Centrifugation
By Mahima Tyagi
M.Sc. Biotechnology
1st sem

2. CONTENT
• Introduction of Centrifugation
• History of Centrifugation
• Principle of Centrifugation
• Types of Centrifugation
• Applications of Centrifugation
• Reference

3. Introduction
• What is centrifugation?
• It is a technique which involves replication of centrifugal force to separate partical from a
solution.
• According to their size, shape, density, viscosity of the median and rotor speed .
• What is centrifuge ?
• A centrifuge is a device that uses centrifugal force to separate various components of a
fluid. This is achieved by spinning the fluid at high speed within a container , thereby
separating fluids of different densities ( eg. Cream from milk ) or liquid from solids .

4. Cont.
• What is centrifugal force ?
• The apparent force that is felt by an object moving in a curved path that acts outwardly
away from the center of rotation.

6. History
• In 1864, Antonin Prandtl ,who developed the first dairy centrifuge for the
purpose of separating cream from milk.
• In 1869, Miescher used a crude centrifuge system to isolate a cell organelles.
• Svedberg in late 1920s developed first analytical ultracentrifugation .
• Technical refinement of the preparative centrifugation technique by Claude
and colleagues in 1940s .

7. Basic principle of Centrifugation
• A centrifuge works by using the principle of sedimentation ( process of
settling down) : under the influence of gravitational force ( g – force ) ,
substances separate according to their density.
• Different types of separation are known including isopycnic, ultrafilteration,
density gradient, phase separation , and pelleting.

8. Cont.
• The rate of sedimentation depends upon applied centrifugal field being
directed radiely outward and is determined by the formula
G = w² r
w = angular velocity of rotor rpm ( rotation per
minute )
r = radial distance of particle from axis of rotation

9. Types of Centrifugation techniques
• There are two types of centrifugal technique for separating particles :
1. Density gradient centrifugation
2. Differential Centrifugation

10. Density gradient centrifugation
• Density gradient centrifugation is a technique in which macromolecules
move through a density gradient until they find a density equal to their own.
• Density gradient centrifugation can further be divided into rate zonal and
isopycnic centrifugation .

11. Rate zonal centrifugation
• In rate zonal centrifugation the solution have a density gradient. The sample
has a density i.e greater than all the layers in the solution.
• The sample is applied in a thin zone at the top of the centrifuge tube on a
density gradient. Under centrifugation force, the particles will begin
sedimenting through the gradient.
• The particles will begin sedimenting in separate zones according to their size,
shape and density.

12. Isopycnic centrifugation
• In this type of Centrifugation, the solution contains a greater range of
densities.
• The density gradient contains the whole range of densities of the particles in
the sample.
• Each particle will sediment only to the position in the centrifuge tube at
which the gradient density is equal to it’s own density.
• In isopycnic centrifugation separation of particules occur into zones on the
basis of their density differences, independent of time.

13. Differential Centrifugation
• Differential centrifugation is a common procedure in microbiology and
cytology used to separate certain organelles from whole cells for further
analysis of specific parts of cells .
• In the process, a tissue sample is first homogenized to break the cell
membrane and mix up the cell contents.
• The homogenate is then subjected to repeated centrifugations, each time
removing the pellet and increasing the centrifugal force .

14. Applications
• To separate two miscible substances.
• To analyze the hydrodynamic properties of macromolecules.
• Purification of mammalian cells.
• Fractionation of subcellular organelles (including membranes/membrane fractions) Fractionation of membrane vesicles.
• Separating chalk powder from water.
• Removing fat from milk to produce skimmed milk.
• Separating particles from an air-flow using cyclonic separation.
• The clarification and stabilization of wine.
• Separation of urine components and blood components in forensic and research laboratories.
• Aids in the separation of proteins using purification techniques such as salting out, e.g. ammonium sulfate precipitation.

16. References
• Principles and Techniques of biochemistry, Wilson and Walker, page no. 74-75,
86-87.
• Slideshare/Sanjay Sinhwar, phd. Research Scholar, department of zoology-
kurukshetra university.
• Slideshare/Dr. Anurag Yadav, Assistant professor, MD Biochemistry and
Consultant Biochemist .
• https://microbenote.com/centrifugation-Principle-types-and-applications/
• https://en.m.wikipedia.org/wiki/Differential-centrifugation