Microcentrifugation

Microcentrifugation is a laboratory technique used to separate components of a liquid sample based on their density and size. It employs a small, high-speed centrifuge specifically designed to accommodate microcentrifuge tubes, often called Eppendorf tubes. These tubes typically hold volumes ranging from 0.1 mL to 2.0 mL. The centrifuge spins the tubes at very high rotational speeds, creating significant centrifugal force. This force causes denser and larger particles to sediment at the bottom of the tube, forming a pellet, while less dense components remain in the supernatant, the liquid above the pellet.

The process involves carefully loading the sample into a microcentrifuge tube, ensuring it is balanced within the centrifuge rotor. The centrifuge is then set to a specific speed (measured in revolutions per minute, RPM, or relative centrifugal force, RCF) and duration, dictated by the nature of the separation required. After the centrifugation is complete, the tube is removed, and the supernatant can be carefully decanted or pipetted off, leaving the separated pellet behind.

Microcentrifugation is a fundamental technique in many biological and chemical laboratories. It is widely used for a variety of applications, including pelleting cells from cell culture media, isolating DNA or RNA from biological samples, separating protein complexes, and purifying small volumes of reagents. The small sample volumes and quick processing times make it an efficient method for routine laboratory procedures. The specific speed and time settings are crucial for achieving optimal separation and are often determined experimentally or based on established protocols.