Phase-separation tube

摘要

A tube (10) for partitioning a pre-selected phase of a sample of liquid having a plurality of phases of differing densities has a smaller diameter at one end (40). In use, a sample of liquid is passed through the first end of the tube and into a first chamber (20) of said tube. The first chamber is separated from a second chamber (21) located at a second opposed end of the tube by a separation device (19) slidably engaging the interior surface of the larger diameter part of the tube in an essentially fluid-tight manner and has a flow-restriction orifice (29) therein to permit fluid flow communication between the first and second chambers under the influence of force. The phases are then ordered within the tube using e.g. axial centrifugation. The volume of the first chamber (20) is reduced by movement of the separation device within the tube, such that one phase of the liquid in the first chamber flows through the flow-restriction orifice and into the second chamber. The method is monitored using the section of the tube that has the smaller diameter, which is transparent.