For the separation effect of the centrifuge, we often consider the type of centrifuge, centrifugation method, centrifugal medium and other factors, but in actual operation, in addition to these points, the centrifuge speed and centrifugation time, as well as the pH and temperature of the centrifugal medium, etc. It is also very important. Let's take a closer look at the impact of the latter three factors on the separation effect.
First, the centrifugation time
Centrifugation time is a very important factor affecting the centrifugal effect. The centrifugation time required for different centrifugation methods will be different. The following is a detailed introduction of differential centrifugation and equal density gradient centrifugation and density gradient centrifugation. For differential centrifugation, the centrifugation time refers to the time when a certain particle completely settles to the bottom of the centrifuge tube; for iso-density gradient centrifugation, the centrifugation time refers to the equilibrium time at which the particle completely reaches the iso-density point; the last one The centrifugation time of the density gradient centrifugation refers to the time for forming a well-defined zone. For the latter two centrifugation methods, the required zone formation time or equilibrium time is complicated, and can be determined after the test.
Second, the centrifugal speed
The rotation speed of the centrifuge is mainly determined by the rotation speed of the rotor and the radius of rotation of the particles. When describing the centrifugal conditions, it is often expressed by the relative centrifugal force field. In actual work, the data of the centrifugal force field refers to the average value, that is, Refers to the centrifugal force field of the particles at the point in the centrifugation solution.
Third, the pH and temperature of the centrifuge medium
The pH value of the centrifugation medium is generally set in the pH range in which the enzyme is stable. A buffer solution can be used. In the test, the weighing is performed, and the environment of the centrifuge itself is corroded by avoiding the environment of peracid or over-base.
When working with a centrifuge, in addition to paying special attention to the choice of centrifugal medium, we must also control the temperature and the pH of the medium solution to prevent agglutination, denaturation and deactivation of the separated substances. We will control the centrifugation temperature to about 4 ° C. For some enzymes with good thermal stability, centrifugation can also be carried out at room temperature.
