The high-speed centrifuge has the advantages of beautiful appearance, large content, small volume, light weight, low noise, small vibration and timing control. It can be used for centrifugal sedimentation separation of plasma, serum, urea and vaccine manufacturing. With the development of molecular biology, genetic engineering research and applications, centrifugal separation technology has also undergone several generations of replacement, from low-speed centrifuges, high-speed centrifuges, ultracentrifuges to ultra-speed refrigerated centrifuges, and ultra-large-capacity refrigerated centrifuges.
The high-speed centrifuge rotates the centrifuge tube containing the non-uniform particles at a high speed in a bench-top large-capacity refrigerated centrifuge. Particles of different sizes and densities are moved to the bottom of the centrifuge tube at their respective sedimentation rates. If a certain speed and time are designed, the sedimentation rate is first settled to the bottom of the centrifuge tube, and the medium sedimentation rate and the smaller components remain in the supernatant. The supernatant is transferred to another centrifuge tube to increase the rotational speed and for a certain period of time, and a medium sedimentation rate component can be obtained. By repeating this operation, separation of different components can be achieved.
The high-speed centrifuge drive system consists of a motor, a drive shaft and a damping mechanism. The AC variable frequency motor is used to seal the pre-lubricated drive shaft, and the shock absorbing mechanism reduces the vibration and noise during the operation of the centrifuge. When the high-end centrifuge prepares the concave side by a concave gradient, contrary to the convex gradient, the first step from the mixing chamber to the centrifuge tube is the heavy-end gradient liquid. When preparing, the light liquid is slowly laid, thus requiring the needle to The corresponding speed is raised. In most cases, simply place the centrifuge tube at a certain angle, and place the needle on the centrifuge tube to make the solution flow down the tube wall gradually, and then gradually spread it. Place the centrifuge tube vertically and load it. At this point it should be noted that the material selected for the centrifuge tube of the high-speed centrifuge is preferably hydrophilic, such as a hydrophobic centrifuge tube, some salt can be used, so that when the gradient solution is added, a uniform flow can be ensured.
Selection of gradient media for high speed centrifuges:
(1) Salt gradient medium.
(2) Small molecule organic matter such as sucrose.
(3) A triiodide benzene derivative.
(4) Organic polymers.
(5) Colloidal silica.
High-speed centrifuge gradient density range:
(1) The density of the medium in the rate zone is smaller than the density of the various particles in the sample.
(2) The density of the medium in the equal density zone is greater than the density of the various particles in the sample.
High-speed centrifuge gradient capacity:
Refers to the maximum number of samples that the gradient medium holds in order to meet the separation requirements.
(1) Related to sample composition and separation requirements.
(2) Related to the total gradient volume, slope, and medium viscosity.
(3) Related to the speed and rotor form.
For high-speed centrifuges for density gradients and sample zone stabilization, the density of the sample added to the top of the density gradient liquid column must be less than the density of the top of the gradient liquid. If not, the sample will pass through the gradient in a collapsed manner until it reaches the iso-density zone. In the process of high-speed centrifuges, the sample layer will expand significantly, and the settlement of the wrapped droplets will cause the zone resolution to decrease.