Abstract: A centrifuge apparatus for separating whole blood into its serum and cell components. The device consists of a small centrifuge cup having a movable bottom wall formed by an upwardly movable piston. The cup is surrounded by a three-tiered ring-shaped container with the two upper tiers each containing a plurality of pockets. The centrifuge cup is spun at a high speed and the whole blood sample in the cup is separated, with excess sample expelled into the lowest tier. The multi-pocketed container is also spun as a centrifuge coaxially with the cup but at a lower speed. The bottom wall piston of the cup and the container are movable vertically relative to the cup by respective cams operated by a common timer-controlled motor.