Since the graduated centrifuge tube is a measuring instrument, it must be cleaned and dried before use. The centrifuge tube and the centrifuge tube should match. The pipe should not be too long, otherwise, it may break when rotating. However, it is not easy to be too short. A tube that is too short is unstable when rotating in the air and can easily cause breakage. If the sleeve is too thick, it will not enter, and it will be unstable when rotating too thin. The round mouth should be larger than the inner diameter of the sleeve.
After the centrifuge tube is put into the centrifuge tube for layer separation, let it stop naturally when stopping the rotation, and never force it to stop by an external force.
Precautions for centrifuge tubes
When we use the centrifuge tube, do not use one tube multiple times, pay attention to sample volatilization and leakage of some radioactive or corrosive samples; in the storage process, it must be sealed well; to prevent the centrifuge tube during use Deformation occurred in the process.
Do not place any material on the centrifuge cover. After each use, be sure to clean the inner cavity and rotor.
If the centrifuge has not been used for a long time, the centrifuge cover should be opened for a period of time before use to dry the inner cavity.
The centrifuge is a conventional laboratory centrifuge, widely used in biology, chemistry, medicine, and other scientific research and education and production departments, suitable for the rapid separation and synthesis of trace samples.
Mobile interface ultracentrifugation
When a sample containing several components is centrifuged in a high enough centrifugal field, each particle reaches its maximum sedimentation velocity, and the sample begins to separate. The upper layer of the centrifuge tube gradually forms a transparent supernatant and forms a series of concentration interfaces corresponding to each component of the sample. The movement of the interface is characteristic of each component.
Although the purification and separation of components may not be achieved by this method, the sedimentation rate of each component can be measured by monitoring the movement of the interface. To achieve separation between the components, the centrifugation process must be stopped after the desired sample has settled. The deposited sample is resuspended in a new solvent and centrifuged at a slower speed to allow large particles of contaminants to settle, while the purified sample remains in the solution. After repeated centrifugation, a pure sample can be obtained. The method is called differential sedimentation centrifugation, which is very useful for separating cell components. The separation of different components can also be achieved by gradually increasing the speed.
The equal density centrifugation method is also called the sedimentation equilibrium method. The so-called iso-density means that the density of the sample is equal to the density of the medium, which is actually carried out in a gradient density medium. The feature of this technology is that the sedimentation separation has nothing to do with the size and shape of the sample material, but depends on the density of the sample material.
This method is very similar to the PH gradient isoelectric focusing method in electrophoresis. During centrifugation, the particles settle or float up according to their density until they move into the solvent gradient with the same density as their own. The result depends on the sample. The difference in material density forms zones in the gradient solvent.
In the experimental method, the method of preparing a density gradient solution in advance can be used. Generally, two stock solutions are prepared first, and their concentration determines the limit of the final gradient solution. The density can be reduced step by step and gradually add the liquid from the bottom to the top of the centrifuge tube to form a discontinuous gradient solution, or a gradient mixer can be used to generate a continuous gradient density. The stock solution is generally prepared using a two-density sucrose solution or a two-density cesium chloride solution. The sample is usually spread on the surface of the solution and then centrifuged.