Small Low-Speed Centrifuges: Operating Details and Safety Rules

In the daily work of a laboratory, the small low-speed centrifuge is often one of the most frequently used basic instruments. Although it appears simple in structure and easy to operate, every step in real applications — from sample balancing to speed setting to status monitoring during the run — hides critical details that affect experimental results and even the instrument's lifespan. To ensure the accuracy of experimental data and extend the life of the instrument, we need to understand the operating logic and maintenance rules behind it.

The core working principle of the small low-speed centrifuge is to use centrifugal force to separate substances in a mixed liquid, and this process places high demands on balance. Before loading samples, the first task is to ensure the centrifuge sits on a solid, flat surface — the foundation for preventing the machine from shifting while spinning. When preparing samples, balancing is a step that must never be ignored. All tubes and their sleeves must be placed in pairs, with the mass error kept within a very small range — a difference of no more than 0.1 g is generally recommended. If there are too few samples to make an even number, a tube filled with distilled water of equal mass must be used for balancing. Place the balanced tubes symmetrically into the rotor holes, and never leave holes empty on one side: asymmetric loads shift the shaft, cause severe vibration, and in serious cases can damage the motor or even break the rotor.

The sample load volume also requires care. Tubes should not be overfilled — the liquid level should normally be one to two centimeters below the rim. Too much liquid is easily thrown out under centrifugal force, which not only contaminates the chamber but may also corrode the rotor. After loading, when closing the lid you must hear the locking click and confirm the lid is fully locked. This step is critical: during high-speed rotation, an unlocked lid could spring open unexpectedly and cause a serious accident.

At start-up, never turn the knob straight to maximum speed or set a high speed and start directly. The correct approach is gradual: first set the speed control to zero, start the machine, and then slowly adjust to the required speed. For certain precision experiments, you can first run at a lower speed for tens of seconds to let the sample pre-settle and reduce bubble formation, then ramp up to the target speed. This slow speed-up strategy effectively reduces current surge, protects the motor, and prevents tubes from rupturing under sudden stress. When setting parameters, set speed and time reasonably according to experimental needs; the speed ceiling of a typical low-speed centrifuge is around 4,000 rpm, which is sufficient for separating most biological macromolecules and precipitates.

While the centrifuge is running, the operator must not leave the site. This is not only to observe experimental progress, but also to listen to the machine. A normal running sound should be a steady hum; if you hear abnormal clicking or metal friction sounds, or feel obvious vibration of the body, cut the power or press the stop button immediately. Never force the lid open at this point — wait until the rotor has stopped turning, then open the lid and check whether the abnormality was caused by a balancing error or a broken tube.

After the experiment, maintenance must not be neglected either. Once the small low-speed centrifuge has stopped, remove the samples and tubes promptly. After every use, be sure to clean residual liquid from the chamber — especially corrosive reagents, which call for wiping the inner wall with distilled water and cleaning the shaft with an alcohol swab to prevent rust. If the centrifuge has not been used for a long time, open the lid and let it dry for a while before reuse to dispel moisture from the chamber. In addition, the rotor, as the core component, needs regular inspection for cracks or signs of aging, and any hidden hazard should be addressed by timely replacement. With standardized operation and careful maintenance — qualities built into Javenlab's low-speed centrifuge range — this seemingly simple instrument will support experimental work stably for years.