Centrifuges spin to generate centrifugal force for separating particles, liquids and other substances with different densities. The denser parts move away from the axis of the centrifuge, while the less dense parts move toward the axis.
The particles that are at the bottom of the sample are the precipitates. The liquid that remains at the top is called the supernatant or supernatant. Depending on the procedure, the sediment or supernatant can be captured by centrifugation.
Common terminology:
Rotational speed. The number of revolutions per minute that a rotor spins.
Screen Centrifuges
RCF: Relative Centrifugal Force. It is a function of the rotor radius and the square of the rotational speed. two centrifuges with comparable RCF values provide the same separation power and are a better way to compare centrifuges than RPM, which is simply a function of the motor's rotational speed. The calculator can determine the RCF by entering the rotational speed and the rotor radius.
Rotors:The rotating parts inside the centrifuge. Generally, these rotors can be removed for cleaning or replaced for different tube/sample sizes or rotor configurations.
Fixed angle rotors:Rotors with tube guards are mounted at a fixed angle. During rotation, the tubes are in an angled position resulting in an angled separation line between the sediment and supernatant.
Horizontal/Oscillating/Oscillating Barrel Spinner:This rotor oscillates horizontally during spinning, creating a flat separation line between the precipitate and the supernatant.
As an important part of your laboratory equipment, it is critical to ensure that you are using your centrifuge correctly and safely.
First, make sure your centrifuge is in proper working condition. It should be calibrated and serviced annually by the Centrifuge Manufacturer or a trained service center. Use a tachometer throughout the year to verify that the rotor is moving at the set speed.
Always operate the centrifuge on a smooth, flat surface with firm footrests.
Always balance cuvettes in the rotor. Unbalanced tubes can damage the equipment at high speeds, causing the tubes to potentially break and/or causing the centrifuge to shake or "walk" on the work surface, resulting in product failure. If balancing with materials of different densities, use tubes of the same material on either side of the rotor and balance by mass rather than volume.
If the centrifuge wobbles or shakes during rotation, unplug it and begin troubleshooting. Make sure the sample load is balanced. If using adapters, make sure all adapters are in place, complete and balanced. Remove the rotor and inspect the bottom of the unit for debris or broken glass. If these checks do not resolve the wobble problem, contact the manufacturer for repair or service options.
Never open the lid of the centrifuge while the rotor is in motion. Many models have safety closures that do not allow opening while in use. However, on some models, you can still open the unit after shutdown, but the rotor continues to spin. A spinning rotor can present a safety issue involving potential hand injuries or accidental projectiles.
Wear goggles when working around the centrifuge to prevent splash/impact injuries. Depending on the chemicals used, face shields can add facial protection from chemical burns. Although a smooth-running centrifuge on the counter may seem safe, protect your face and eyes from any splashes or impacts if a centrifuge tube or rotor malfunctions.
Keep the centrifuge in a safe place so that it cannot be hit by others during operation. Move cords out of high-traffic areas so that the centrifuge will not be pulled out or tripped over on the counter top.
By choosing the right model for your needs and using it safely, the centrifuge can become a staple in your lab for years to come. We also offer decanter centrifuges and Screen Centrifuges, so please feel free to contact us if you need one!
