Centrifuges (Benchtop, Refrigerated, Plate, Clinical)

Separations are defined by relative centrifugal force rather than speed alone, since force depends on both the speed and the rotor radius. Pelleting cells needs modest force, while pelleting fine precipitates or membranes needs much higher force. Check the maximum force the machine reaches with the rotor you would use. Give the seller your target force and sample type so they can confirm the machine reaches it.

The rotor and drive are the critical parts, so ask whether the rotor is within its service life and free of cracks or corrosion. Aluminium rotors have a limited number of runs and should carry a log. Listen for smooth running and check that the machine reaches and holds set speed. A recent service and a rotor with life remaining make for a sound purchase.

You need cooling whenever your samples contain heat sensitive material such as enzymes, proteins or live cells, because high speed spins generate heat. Long runs in particular can warm a chamber enough to damage labile targets. If your work is heat stable, an ambient machine is simpler and cheaper. Tell the seller what you spin so they can advise whether refrigeration is worthwhile.

The rotor and its adapters decide which tube sizes and plate formats a machine takes. A machine is only useful if the right rotor and buckets come with it or are available. Check which rotors the listing includes and whether adapters for your consumables exist. Ask the seller to confirm the rotor options so your tubes and plates fit.

Sellers on the marketplace are verified, and you deal with them directly with no middleman in between. You can ask for photos of the rotor, a service record and a video of the machine spinning up. That direct exchange lets you confirm the condition before you commit. Agree any inspection you want in advance.