How many commonly used centrifugal separation methods do you know?

How many commonly used centrifugal separation methods do you know? A centrifuge is a machine that uses centrifugal force to separate components from liquid and solid particles or a mixture of liquid and liquid
.

Centrifuges are mainly used to separate solid particles from liquids in suspension, or to separate two immiscible liquids with different densities in emulsions (such as separating cream from milk); it can also be used to remove Liquid in wet solid
.

So, do you know what are the commonly used centrifugal separation methods? Let’s find out with me below
.

Commonly used centrifugal separation methods ① Differential centrifugation Differential centrifugation mainly adopts the method of gradually increasing the centrifugal speed to separate the structures of different densities in the sample, such as mitochondria, chloroplasts, proteins, etc.
! Step 1: Set the initial centrifugation speed to be low, let the larger particles settle to the bottom of the tube first, and the small particles are still suspended in the supernatant
.

The second step: collect the precipitate, use a higher centrifugal speed to centrifuge the suspension, settle the smaller particles, and so on, to achieve the purpose of separating particles of different sizes
.

Advantages: The processing capacity of the sample is large, and it can be used for the initial separation of a large number of samples
.

Disadvantages: When separating complex samples and requiring high separation purity, the number of centrifugation is many and the operation is complicated.
Due to the repeated washing, dissolution and re-precipitation of the precipitate, it is easy to cause intermediate losses, so the centrifugal resolution is poor
.

② Gradient centrifugation Density gradient centrifugation is to add the sample to the centrifuge tube to increase the gradient medium in advance for velocity sedimentation or sedimentation balance, and distribute the particles to certain specific positions in the gradient under the centrifugal force to form the separation of different zones method
.

 　　The commonly used media for density gradient centrifugation are cesium chloride, sucrose and polysucrose Advantages: good resolution and good separation effect; particles will not be backlogged and deformed, can maintain particle activity, and prevent the formed zone from being destroyed by convection.
Causes mixing; has a wide range of adaptability, that is, it can separate particles with poor sedimentation coefficients and particles with buoyant density
.

 　　Disadvantages: The sample concentration should not be too high; the time to reach equilibrium is long
.

 　　③ Analytical ultracentrifugation Analytical ultracentrifugation is mainly to study the sedimentation characteristics and structure of biological macromolecules, rather than to collect a specific component
.

It therefore uses special rotors and detection means in order to continuously monitor the sedimentation process of substances in a centrifugal field
.

Analytical ultracentrifuges are mainly composed of an elliptical rotor, a vacuum system and an optical system
.

The rotor is coupled to a high-speed drive by a flexible shaft that allows the rotor to form its own shaft as it rotates
.

 　　Advantages: Accelerate the sedimentation rate of particles in the liquid, and separate substances with different sedimentation coefficients and buoyancy densities in the sample
.

 　　Disadvantages: It is necessary to use a centrifuge to generate a strong centrifugal force to force these particles to overcome the diffusion and produce sedimentation.
The above is the relevant introduction to the commonly used centrifugal separation methods.
I believe that everyone has a corresponding understanding of this after reading, and different centrifugal separation methods are applicable.
The test is different, and the selection should be considered in combination with the actual situation, and I hope it will be helpful to everyone
.