I. Centrifuge Operating Procedures
1. When using any centrifuge, the centrifuge tubes and their contents must be precisely balanced on a balance beforehand. The weight difference during balancing must not exceed the range specified in the centrifuge's instruction manual. Each centrifuge's different rotors have their own allowable tolerances. An odd number of tubes cannot be loaded into the rotor. When the rotor is only partially loaded, the tubes must be placed symmetrically in the rotor to ensure that the load is evenly distributed around the rotor.
2. If centrifugation is to be performed at a temperature below room temperature, the rotor should be pre-cooled in a refrigerator or in the centrifuge's rotor chamber before use.
3. Do not leave the centrifuge unattended during centrifugation. Always observe the instruments on the centrifuge to ensure they are working properly. If any abnormal sounds are heard, stop the machine immediately, check for problems, and resolve them promptly.
4. Each rotor has its own maximum allowable speed and cumulative usage time limit. When using a rotor, consult the instruction manual and do not exceed the maximum speed. Each rotor should have a usage log to record the cumulative usage time. If the maximum usage time limit for the rotor is exceeded, the speed must be reduced as required.
5. When loading solutions, follow the specific operating instructions for each centrifuge. Select suitable centrifuge tubes based on the properties and volume of the liquid to be centrifuged. Some centrifuge tubes do not have lids; do not overfill them to prevent liquid from splashing out during centrifugation, which could cause rotor imbalance, rust, or corrosion. For preparative ultracentrifuges, the centrifuge tubes often require being completely filled to prevent the upper part of the plastic centrifuge tube from deforming during centrifugation. After each use, the rotor must be carefully inspected, cleaned, and dried. The rotor is a key component of the centrifuge that requires careful protection. Handle it carefully and avoid collisions to prevent damage. When the rotor is not in use for a long time, apply a layer of protective wax. The use of significantly deformed, damaged, or aged centrifuge tubes is strictly prohibited.
II. Centrifuge Safety Guidelines
Safety is paramount when using a centrifuge. Uncontrolled centrifugal force can cause significant damage. Therefore, pay attention to whether the centrifuge tubes are balanced, whether the speed exceeds the set limit, and whether the rotor is corroded, etc. Centrifuges may seem simple to use and require no technical expertise, but proper use and maintenance are essential. A malfunction can cause delays in experiments, resulting in significant losses.
1. When the centrifuge is in pre-cooling mode, the centrifuge lid must be closed. After centrifugation, the rotor should be placed upside down on the lab bench, and any remaining water in the chamber should be wiped dry. The centrifuge lid should remain open at this time.
2. During pre-cooling, the rotor lid can be placed on the centrifuge platform or on the lab bench. It must never be loosely placed on the rotor without being tightened, as accidental activation could cause the lid to fly off, leading to an accident!
3. After tightening the rotor lid, always check with your fingers for any gaps between the rotor and the lid. If there are gaps, unscrew and retighten until no gaps are present before starting the centrifuge.
4. During centrifugation, the operator must not leave the centrifuge room. In case of any abnormal situation, the operator should not turn off the power, but press the STOP button. The centrifuge usage log must be filled out before pre-cooling.
5. Do not use substandard centrifuge tubes, or tubes that are aged, deformed, or cracked.
6. On holidays and at the end of the day, the last person using the centrifuge must perform a routine safety check before leaving.
7. If machine malfunctions or component damage occurs during instrument use, contact the manufacturer immediately.
III. Daily Maintenance of the Centrifuge
1. Before operating the centrifuge, the power should be switched off and the centrifuge brake released. The drum can be rotated manually to check for any jamming. Check other parts for looseness or abnormalities. Connect the power and start the machine in a clockwise direction (usually it takes about 40-60 seconds from standstill to normal operation). Each unit usually requires about 3 hours of empty running after delivery to the factory; if there are no abnormalities, it can be put into operation.
2. The material should be placed as evenly as possible, and operation must be performed by trained personnel. The capacity must not exceed the rated amount.
3. The mesh size of the filter cloth should be determined according to the size of the solid particles of the material being separated; otherwise, it will affect the separation effect. Additionally, when installing the filter cloth, the filter cloth sealing ring should be embedded in the drum sealing groove to prevent material leakage.
4. To ensure the normal operation of the centrifuge, the rotating parts should be lubricated and maintained every 6 months. At the same time, check the lubrication of the bearings for any signs of wear; check the components of the braking device for wear, and replace severely worn parts; check the bearing cover for oil leaks.
5. After using the machine, it should be thoroughly cleaned to maintain its cleanliness.
6. Do not use non-corrosion-resistant centrifuges for separating highly corrosive materials; also, strictly follow the equipment requirements and operating procedures. Non-explosion-proof centrifuges must not be used in flammable or explosive environments.