Microcentrifuges

A microcentrifuge is a compact bench-top centrifuge designed to operate with small-volume tubes, typically 0.2 to 2.0 mL. It uses high-speed rotation of a rotor to generate centrifugal force that separates components by density. The rotor can be fixed-angle, where tubes sit at a constant angle, or swing-bucket, where tubes move to a horizontal position during operation. The force is described as relative centrifugal force (RCF) or g, calculated roughly by RCF = r (2πN/60)^2, where r is the rotor radius in meters and N is the speed in revolutions per minute.

Common uses include pelleting cells from culture, clarifying lysates, concentrating nucleic acids or proteins, removing debris, and preparing samples for downstream analyses such as PCR, sequencing, or gel electrophoresis. The small tube volumes and rapid spin times make microcentrifuges essential for routine molecular biology and clinical laboratory workflows.

Specifications vary by model. Most microcentrifuges reach tens of thousands of x g, with maximum rotor speeds commonly in the range of 10,000 to 30,000 rpm, depending on rotor radius and design. Some models offer higher speeds, refrigerated versions maintain low temperatures for temperature-sensitive samples, and non-refrigerated units are common for quick spins. Attachments include rotors for different tube sizes and adapters that expand capacity.

Safety and maintenance emphasize balanced loads, proper rotor selection compatible with tube type, routine rotor cleaning, and inspection for wear or cracks. Damaged rotors or tubes should be replaced promptly to prevent failure and injury.