Abstract: An analytical rotor for separating cellular components from a biological fluid includes a separation chamber spaced radially outward from a sample chamber. The sample chamber may be an open receptacle disposed to receive sample or may be a mixing chamber which receives sample and diluent. A flow restrictive channel connects the sample chamber to the separation chamber so that fluid enters the separation chamber at a controlled rate. The cellular components collect within a retention region located generally at the outer periphery of the collection chamber while cell-free fluid is continuously removed through a collection port. The collection port is spaced annularly apart from the flow channel so that there is sufficient residence time within the separation chamber for substantially complete separation of the cells from the fluid fraction.

Abstract: A centrifugal rotor comprising a plurality of peripheral cuvettes and a collection chamber spaced radially inward from the cuvettes is disclosed. The rotor includes a means for introducing fluid into the collection chamber and plurality of generally radial inlet channels connecting each cuvette to the chamber. Each inlet channel has a discrete flow path for fluid to enter the cuvette and another discrete flow path for gas to exit the cuvette as the cuvette is filled. Positioned radially inward from each cuvette is a reflective surface capable of deflecting a light beam from a generally vertical direction to a generally horizontal direction or vice versa. As the rotor is spun, fluid enters the cuvettes from collection chamber through the inlet channels, which also allow gas in the cuvettes to escape, thus avoiding the creation of bubbles in the cuvette after the cuvettes are filled. The contents are then optically analyzed by passing a light beam horizontally through the cuvette.

Abstract: A centrifugal rotor for separating plasma from whole blood includes a plurality of internal chambers and passages for combining the plasma with one or more reagents and distributing the plasma to a plurality of individual test wells. The chambers and passages necessary for separating the whole blood into plasma are located on a first, upper level within the rotor and include a measuring chamber, an overflow chamber, a separation chamber, and a reagent chamber. The measuring chamber and overflow chamber have capillary dimensions so that an initial volume of whole blood partitions therebetween, with the measuring chamber filling first to provide a preselected volume. The separation chamber is located radially outward from both the measuring chamber and the reagent chamber to that spinning of the rotor causes both the reagent and the measured blood volume to flow outward into the separation chamber.