Abstract: A centrifuge tube assembly which allows for a single centrifuge cycle and which permits the aspiration of fluids from multiple levels with the centrifuge tube assembly. The centrifuge tube assembly includes a vertically disposed outer containment tube having a closed lower end and an open upper end with the open upper end being closed by a cap. An elongated inner tube extends downwardly through the cap and into the interior of the outer containment tube. A generally cone-shaped disk assembly is slidably mounted on the inner tube to create a chamber above the disk assembly. An O-ring is mounted on the lower end of the disk assembly which is in yieldable engagement with the inner tube. A flapper valve is positioned in the upper end of the disk assembly. The flapper valve has a plurality of slits formed therein.

Abstract: A centrifuge tube assembly which allows for a single centrifuge cycle and which permits the aspiration of fluids from multiple levels with the centrifuge tube assembly. A modified centrifuge assembly is described wherein the inner tube has an externally threaded portion at its upper end. The method of using the centrifuge tube assembly is also described wherein the centrifuge tube assembly may be used for the aspiration, separation, isolation and extracting of discrete layer in a liquid suspension.