What is Centrifuge ？
Laboratory centrifuge is a kind of experimental equipment that accelerates the settling speed of substances and realizes the separation of different molecular particles by rotating the object around a fixed axis and making it subject to centrifugal force.
Centrifuge is widely used in chemical, food, pharmaceutical, environmental protection, teaching, medical and other scientific research and production departments, playing a very important role in the separation and extraction of substances, has become one of the important instruments and equipment of modern scientific research, but also biology, biochemistry, medicine, biological engineering, biopharmaceuticals and other industries necessary for scientific research and production equipment.
Centrifugation is a technology that uses centrifugal force to separate particles / substances with different sedimentation coefficients from a solution.
Centrifuge is the application of the principle of centrifugation, according to the size, shape, density, solution viscosity and other differences in the particles, through the high-speed rotation of the rotor on the centrifuge to generate a strong centrifugal force to accelerate the settling speed of different specific gravity components in the mixture, the sample of different sedimentation coefficients and buoyancy density of the material separation or stratification and classification, the centrifugation process of particles with higher density will be thrown more quickly to the outside of the centrifuge tube, while lighter particles will move to the center, so that the solid particles or liquid components of different densities in suspension can be separated.
Application of Centrifuge in the Study of Corona Virus
At the beginning of 2020, Peking Union Medical College Hospital published the guidelines for operating the Coronavirus. The following is the official reference procedure for virus sample lysis:
1. Using a 1.5ml sterile centrifuge tube (EP tube), pipette 560μl of AVL lysate and add 5.6μl of Carrier RNA and 140μl of inactivated nucleic acids to be extracted from the sample to be tested, vortex shake for 15s and leave for 10min at room temperature.
2. Place the above EP tubes into a centrifuge and centrifuge instantaneously to remove any lysis products that may remain on the lid of the EP tubes to prevent contamination.
3. After lysis, add 560μl of anhydrous ethanol to the EP tube and mix with shaking for 15s
4. Centrifuge the EP tube again to remove any lysis products that may remain on the EP tube lid to prevent contamination
5. Add 630 μl of lysis product to the centrifuge column and centrifuge at 8000 rpm for 1 min.
6. To replace the waste collection tube, carefully remove the centrifuge column from the centrifuge, transfer the upper column to a new collection tube, continue to add 630μl of the remaining lysis product to the column, repeat this step if the sample volume is greater than 140μl, until all the lysis product is centrifuged through the column at 8000rpm for 1min, and then carefully transfer the column to a new collection tube
7. Add 500 μl of AW1 to the centrifuge column (note that the sample must be added slowly with the pipette tip touching the inner wall of the column), centrifuge at 8000 rpm for 1 min, carefully remove the column and replace the collection tube with a new one.
8. Add 500 μl of AW2 to the column, centrifuge at 14000 rpm for 3 min, carefully remove the column, replace the collection tube at the top of the column with a new one, and centrifuge at maximum speed for 1 min to ensure that the residual liquid in AW2 is completely centrifuged.
9. Take a sterile 1.5 ml EP tube to collect the nucleic acid. Carefully place the upper end of the column into the 1.5 ml EP tube, add 40-60 μl of the eluate AVE to the column (note: the eluate should cover the column membrane as much as possible), cover the column with the cap of the EP tube, and use sterile scissors to cut off the cap of the original column.
10. Allow to stand at room temperature for 1min, then centrifuge at 8000rpm for 1min to recover the nucleic acid.
11. Discard the centrifuge column, and the nucleic acid we want to extract is now in the EP tube, and then mark and register it well.
During the lysis process of virus samples, it is recommended to use centrifuges in biosafety cabinets throughout the process, which can effectively prevent the trouble caused by sample leakage and contamination. The speed of centrifuges used in experiments needs to reach 8000rpm and above, which are high-speed centrifuges and should be adaptable to low-capacity EP tubes. HK iFuge M24 PR micro high-speed centrifuge and UVC/T-M-AR universal ultra clean bench can meet the above requirements.