Selection precautions:

1. Speed:

Domestic desktop centrifuges are divided into low-speed centrifuges (<10000rpm/min), high-speed centrifuges (>10000rpm/min to 30000rpm/min), and ultra high speed centrifuges (>30000rpm/min) based on their different rotational speeds. Each centrifuge has a rated speed.

The speed refers to the speed under no-load conditions, but it varies depending on the type of rotor and the size of the sample mass. For example, if the rated speed of a centrifuge is 16000rpm/min, it means that the rotor rotates 16000 times per minute when unloaded. After adding the sample, the speed will definitely be less than 16000rpm/min. The speed varies depending on the type of rotor. A centrifuge can be equipped with multiple rotors, and the separation effect of the centrifuge mainly depends not on the speed, but on the centrifugal force. Therefore, sometimes the speed does not meet the requirements, as long as the centrifugal force can meet the standard, it is the same. During the experiment, the desired effect can be achieved.

2. Temperature

Some samples (such as proteins, cells, etc.) can be damaged in high temperature environments, so it is necessary to choose a cryogenic centrifuge, which has a rated temperature range. The heat generated by a centrifuge during high-speed operation and the refrigeration system of the centrifuge are balanced at a certain temperature (generally, frozen centrifugal samples need to be kept at 3 ℃~8 ℃), and the specific amount that can be achieved depends on the rotor. For example, the rated temperature range of a centrifuge is -20 ℃~40 ℃. When a horizontal rotor is installed and rotated, it can reach about 3 ℃, and if it is an angle rotor, it may reach about 7 ℃, The specific situation depends on the set temperature, speed, and rotor.

3. Capacity

How many sample tubes need to be centrifuged each time, and how much capacity is required for each sample tube, these factors determine the total capacity of a centrifuge. Simply put, the total capacity of a centrifuge is equal to the capacity of each centrifuge tube multiplied by the number of centrifuge tubes. The total capacity and workload are matched.

4. Rotor

The rotors of laboratory centrifuges are mainly divided into two types: horizontal rotors: during operation, the suspension basket and test tube are in a horizontal state, at right angles to the rotation axis, and the sample will concentrate at the bottom of the centrifuge tube. Angle rotor: The centrifugal container is at a fixed angle with the shaft, and the sample will concentrate sediment at the bottom of the centrifuge tube and the side walls near the bottom. If you want the separated sample to be concentrated at the bottom of the centrifuge tube, choose a horizontal rotor. If you want the sample to be concentrated at the bottom of the centrifuge tube and the side wall near the bottom, choose an angle rotor. Some special experiments or samples require special rotors, such as high-capacity hanging baskets (mostly used in blood stations), enzyme-linked immunosorbent assay (ELISA) plate rotors, slide rotors, PCR rotors, test tube rack rotors, and capillary rotors. Rotors have fixed specifications, which are combined with the capacity of the centrifuge. For example, a 36 × 5ml angle rotor determines both the type of rotor and the capacity of the centrifuge. In addition, rotor materials are also divided into engineering plastics, stainless steel, aluminum alloy, titanium alloy, and other materials. The different materials selected directly determine the price, speed, and service life of the rotor, so the selection of the rotor is very important.