Centrifuge with orbiting bobbins

This disclosure concerns an invention relating generally to centrifuges. A centrifuge includes a rotor around which a plurality of bobbins rotate. Each bobbin bears one or more fluid-carrying passages through which liquid analyte is passed for centrifuging. Supporting the bobbins on the rotor is a support member which provides a cylindrical inner surface. The inner surface supports the bobbins on rotation thereof to prevent high frictional torques from the bearings of the bobbins.