Floor-standing centrifuges free up bench space but do need at least one square meter of lab floor space. They are a good choice for high-speed or high-capacity protocols. Among floor-standing centrifuges, choices include ultracentrifuges, super-speed centrifuges, and low-speed centrifuges. An ultracentrifuge is a device for exceptionally high speed. These refrigerated centrifuges have an evacuated chamber to enable a rotational speed of up to 150,000 rpm. The g-force is about 300,000 to 1,000,000 × g. Special vessels that are placed within the rotor or attached to a special rotor are necessary. When g-forces of 40,000 to 60,000 × g are needed, super-speed floor-standing centrifuges are to be used. Low-speed floor-standing devices are generally used for applications like cell culture or blood with less than 10,000 rcf as the maximum g-force.
Bench-top centrifuges are available in different sizes:
Microcentrifuges are optimized for low-volume tubes, have a small footprint, and provide 14,000 to 30,000 × g for up to 48 microtubes. Some devices can even be used for a few 15 mL or 50 mL conical tubes or 2 SBS-format plates. Many suppliers offer non-refrigerated and refrigerated versions and different sizes of devices based on their tube capacity.
Offering a bigger rotor chamber, multipurpose centrifuges allow a broad range of rotors to be used (highly versatile). In addition to a flexible rotor system, specific adapter systems enable use of a wide variety of different kinds of tubes and bottles (from 0.2 mL to 1,000 mL) as well as plates. The maximum speed heavily depends on the vessel’s characteristics.