How to choose a centrifuge?
(1) Temperature: Some samples (such as proteins, cells, etc.) will be destroyed under high temperature conditions. This is to choose a refrigerated centrifuge. The refrigerated centrifuge has a rated temperature range. The heat generated by the centrifuge at high speed is balanced with the refrigeration system of the centrifuge at a certain temperature (the sample for general freeze centrifugation needs to be kept at 3 ° C ~ 8 ° C), and the specific amount can be related to the rotor, such as a centrifuge The rated temperature range is -10 °C ~ 60 °C, and the horizontal rotor can be rotated to about 3 °C. If it is an angular rotor, it may only be about 7 °C. Please consult the product sales personnel and the manufacturer. Technical staff.
(2) Rotating speed: The centrifuge is divided into low speed centrifuge (<10000rpm/min), high speed centrifuge (10000rpm/min 30,000rpm/min) and ultra high speed centrifuge (>30000rpm/min) according to the maximum speed. The centrifuge has a rated maximum speed, and the maximum speed refers to the speed under no-load conditions, but the maximum speed varies depending on the type of rotor and the quality of the sample. For example, the rated speed of a centrifuge is 16000 rpm/min, indicating that the rotor rotates 16,000 times per minute at no load. After adding the sample, the speed will definitely be 16,000 rpm/min. The rotor is different, the maximum speed is different, the horizontal rotor can reach 15000 rpm/min, but the angle rotor can reach 14000 rpm/min. The specific difference should be consulted in detail with the product sales personnel and the relevant technical personnel of the production plant, so the choice of the speed Be cautious, the maximum speed of the selected centrifuge should be higher than the target speed. For example, the target speed is 16000 rpm/mIn, and the maximum speed of the selected centrifuge must be higher than 16000 rpm/min.
(3) Rotor: The rotor of the centrifuge is mainly divided into two types: horizontal rotor: the hanging blue is in a horizontal state during operation, at right angles to the rotating shaft, and the sample concentrates the sediment on the bottom of the centrifuge tube: the angle rotor: the centrifugal container is fixed with the rotating shaft At the angle, the sample concentrates the sediment on the bottom of the centrifuge tube and the side wall near the bottom. If you want the separated sample to be concentrated at the bottom of the centrifuge tube, select the horizontal rotor. If you want the sample to concentrate on the bottom of the centrifuge tube and the side wall near the bottom, select the angle rotor. There are also special tests or special samples that require special rotors such as large-capacity baskets (used for blood stations), enzyme-labeled rotors, slide rotors, PCR rotors, test-tube rotors, and capillary rotors. The rotor has a fixed size, which is combined with the capacity of the centrifuge, such as the 36 × 5ml angle rotor, which determines the type of rotor and determines the capacity of the centrifuge, so the choice of the rotor is very important.
(4) Capacity: How many sample tubes need to be centrifuged each time 7 How much capacity is needed for each sample tube 7 These factors determine the total capacity of a centrifuge, simply the total volume of the centrifuge = the capacity of each centrifuge tube × Centrifugation The number of tubes, the total capacity and the size of the workload are matched.
(5) Control system: High-end centrifuges use microcomputer control systems. These control systems not only ensure the safe operation of the centrifuge but also automatically complete the task. Many centrifuges now have better humanized control systems, such as rotor recognition, safety lock function, fault prompt function, acceleration and deceleration curves, and so on. In addition to the above points, pay attention to some details and necessary accessories. The main components of the centrifuge are motors. The motors are divided into carbon brush motors and carbonless brush motors. The former has been eliminated. Most of the current centrifuges are brushless motors, and some motors also have brake functions. Refrigerated centrifuges also differ in refrigeration, and now environmentally friendly technologies are of course fluorine-free refrigeration.
In addition to this, consider the noise problem and try to choose a quieter centrifuge to maintain a comfortable experimental environment. Care should be taken in the accessories. In some experiments, special centrifuge tubes (centrifugal toxic samples or samples requiring ultra-high-speed centrifugation) should be used. Such centrifuge tubes must be equipped with corresponding sleeves for safety. There are also some special sample containers (irregular vials, blood bags, etc.). These details and accessories should be carefully considered when selecting a centrifuge, otherwise normal operation will not be possible.