Benchtop centrifuges: choosing by rotor range rather than top speed, and the refrigeration, noise and bench-fit questions that follow

Specifying from the rotors

1. List the vessels and the forces first. Write down every tube, bottle and plate the machine must spin and the force each protocol requires. That list determines the rotor set, and the rotor set determines which machines are candidates. Working the other way round produces a machine that cannot run one important protocol.
2. Top speed is a rotor property. Advertised maximum speed usually applies to the smallest rotor. Ask for the maximum relative centrifugal force in each rotor you intend to buy, since that is what a protocol specifies and what limits the instrument in practice.
3. Refrigeration if anything is temperature sensitive. Enzymes, live cells, nucleic acids and long spins all need cooling, and frictional heating raises sample temperature noticeably during a long run even in a cool room. A refrigerated unit costs more to buy, run and site, and a laboratory that needs it and does not buy it will buy twice.
4. Plate capacity and swing-out geometry. If plates are spun, confirm the machine takes them, how many, and at what depth, including deep well and sealed plates. Plate spinning is a common late requirement and not every benchtop unit accommodates it.
5. Noise, heat and bench footprint. These machines are loud and vent heat, and a shared bench in a quiet laboratory is a poor location. Check the footprint with the lid open, since that is the space it actually needs.

Containment for hazardous samples

Sealed buckets or a sealed rotor lid keep an aerosol contained if a tube fails and allow the rotor to be opened in a cabinet. For human, infectious or toxic material this is a requirement rather than an accessory, and it should be specified with the machine.

Confirm the sealed carriers are available for the rotors you are buying, since they are not offered for every rotor in every range.

Rotor life and consumable cost

Rotors log cycles, corrode and are retired on manufacturer rules, and a replacement rotor is a significant fraction of the machine price. Ask what the retirement policy is, how cycles are logged, and what rotors cost before the purchase rather than after.

Adapters for different tube sizes are cheap and easily lost. Order spares with the machine and keep them with the rotor rather than in a drawer.

Common questions

How do I choose a benchtop centrifuge?

From the rotors. List every vessel and every force your protocols require, and let that determine the rotor set and therefore the candidate machines. Advertised top speed applies to the smallest rotor only.

Do I need refrigeration?

If you spin enzymes, live cells, nucleic acids or anything for an extended period, yes. Frictional heating raises sample temperature during long runs even in a cool room.

Can a benchtop centrifuge spin plates?

Many can with the right swing-out rotor, but not all, and deep well or sealed plates may not fit. Confirm plate capacity and depth explicitly if plates are in your protocols.

When are sealed buckets required?

Whenever a tube failure could release an infectious or toxic aerosol, including most work with human material. They also allow the rotor to be opened inside a biosafety cabinet.

Browse by service class

• Compare Gene synthesis on advertised prices