Method and apparatus for sequential fractionation

摘要

An apparatus for sequentially fractionating a centrifuge tube includes a capillary tube and a means for applying positive pressure. The capillary tube has an O-ring at the lower end thereof. As the capillary tube is placed within the centrifuge tube, the O-ring forms a seal within the tube. Movement of the capillary tube within the centrifuge tube places the liquid in the centrifuge tube under pressure, thus forcing the liquid to flow up through the capillary tube and into a chamber. A chase fluid is then pumped horizontally through the chamber to force the liquid therein through an exit port and into a fraction collector. The apparatus and method of the present invention may be entirely automated and controlled by a single microprocessor.