The
centrifuge is one of the commonly used general experimental instruments in laboratories. It is widely used in biomedicine, experimental research, petrochemical industry, agriculture, food hygiene and other fields. Many laboratories often focus on analytical instruments and ignore basic equipment. However, although basic equipment has functions Simple, but equally important - whether the sample processing is precise or not, whether the dry and wet conditions of the materials meet the standards, etc. will all affect the experimental results.
Classification of centrifuges:
There are three ways to classify centrifuges: by use, by speed and by structure.
1. Classification by use: divided into preparative centrifuges and preparative analytical centrifuges.
1) Preparative centrifuge: a centrifuge only used for separation, concentration and purification of samples.
2) Preparation and analysis centrifuge: a centrifuge that can not only separate, concentrate, and purify samples, but also observe, photograph, measure, digital output, and print the sedimentation process of the sample through an optical system.
Classified by speed: divided into low-speed centrifuges, high-speed centrifuges, and ultra-speed centrifuges.
1) Low-speed centrifuge: the rotation speed is within 10,000 rpm or the relative centrifugal force is within 15,000 × g.
2) Medium-speed centrifuge: the rotation speed is within 10000∽30000rpm or the relative centrifugal force is within 15000∽70000×g.
3) Ultracentrifuge: The rotation speed is above 30,000 rpm or the relative centrifugal force is above 70,000 × g.
2. The centrifuge mainly consists of the following parts:
Base: It is the support part of the centrifuge, usually made of steel structure, which is stable and reliable.
Centrifuge rotor: It is the main part of the centrifuge and is used to hold samples. It is usually made of glass or plastic.
Motor: Provides power for the rotation of the centrifugal rotor. Brushless motors are usually used to reduce noise and vibration.
Control system: used to control centrifuge speed, time, temperature and other parameters, usually controlled by a microprocessor, which can accurately control experimental conditions.
Protection device: including electronic protection device and mechanical protection device, used to protect the safety of the centrifuge under abnormal conditions.
3. Working principle of centrifuge
The centrifuge generates a centrifugal force field through high-speed rotation to separate materials of different densities and masses. The sample inside the centrifuge moves toward the edge of the rotor under the action of centrifugal force, forming sediments at different levels. Centrifuges are generally divided into two types:
Conventional centrifuge: mainly used for conventional sample separation, precipitation and purification. The rotation speed is generally between 5000~30000rpm.
High-speed centrifuge: mainly used for the separation and purification of experimental samples that require high speed and high centrifugal force conditions, such as dense particles or microorganisms. The rotation speed is usually between 30000~50000rpm.
4. How to use centrifuge
Prepare the sample: Add the sample to be separated into the centrifuge tube, being careful not to exceed the capacity limit of the centrifuge tube.
Select centrifuge tubes: Choose appropriate centrifuge tubes according to experimental requirements. Commonly used centrifuge tubes include glass centrifuge tubes, polypropylene centrifuge tubes, etc.
Place the sample: Place the centrifuge tube into the centrifuge rotor, being careful not to exceed the capacity limit of the centrifuge tube.
Set parameters: Set centrifuge speed, time, temperature and other parameters according to experimental requirements.
Start centrifugation: Press the centrifuge start button to start centrifugation.
Turn off the centrifuge: After centrifugation, turn off the centrifuge and take out the sample.
Organize the experimental table: Clean the experimental table and keep the laboratory tidy.
Clean the centrifuge tube: Choose the appropriate cleaning method according to the material of the centrifuge tube and clean it.
Store centrifuge tubes: Store centrifuge tubes in a dry, clean place.
5. Precautions for centrifuge
When using a centrifuge, be careful not to exceed the centrifuge capacity limit to avoid accidents.
When choosing a centrifuge, you should choose the appropriate centrifuge tube according to the experimental requirements, and pay attention to the material and cleaning method of the centrifuge tube.
When setting the centrifuge parameters, the selection should be based on the experimental requirements and the actual situation of the centrifuge.
During the centrifugation process, pay attention to the operating status of the centrifuge. If there is any abnormality, stop the centrifuge in time.
When cleaning centrifuge tubes, be careful not to use corrosive solvents to avoid damaging the material of the centrifuge tubes.
When storing centrifuge tubes, be careful to avoid contamination from the external environment and keep them dry and clean.
6. Maintenance of centrifuge
Centrifuge maintenance is essential to ensure the normal operation of the equipment and extend its service life. Clean the centrifuge chamber and rotor after each use to avoid sample residue. Use mild detergent and soft cloth to wipe. Do not use highly corrosive chemicals. Regularly check the rotor for cracks, corrosion or other damage, and ensure that the rotor and centrifuge tube are installed in a balanced manner to avoid eccentric operation. Check and lubricate the rotor and bearings regularly, using the lubricant recommended by the manufacturer. Calibrate the centrifuge regularly according to the manufacturer's recommendations to ensure speed and temperature accuracy. Regularly replace aging or damaged parts, such as seals, gaskets, etc., based on frequency of use and manufacturer recommendations. Use the centrifuge strictly in accordance with the operating manual to avoid overloading. During operation, do not open the centrifuge cover to avoid accidental injury. If abnormal vibration or noise is found, stop the machine immediately for inspection to ensure that the emergency stop button and protective device are working properly. Place the centrifuge in a dry, well-ventilated environment, avoid direct sunlight and moisture, keep the surrounding environment clean, and prevent dust and impurities from entering the equipment. When not in use for a long time, clean the centrifuge and store it, and apply anti-rust oil to the rotor. Record the details of each maintenance, maintenance and repair, including replaced parts and lubricant usage, and check the records regularly to ensure that maintenance work is carried out as planned. Through the above steps, you can effectively extend the service life of the centrifuge and ensure its stable and safe operation. If you have any questions or special issues, it is recommended to consult the equipment manufacturer or professional technicians.
By understanding the working principle of the centrifuge and its correct use, the accuracy and safety of the experiment can be effectively improved and the service life of the equipment can be extended.
