Abstract: The method of rapidly separating plasma or serum from red blood cells comprising the steps of mounting a pair of spaced apart tubes coaxially related to one another head-to-head with a sharp-ended hollow needle disposed generally along the tube axes and between them, arranging the tubes in a vertical position one above the other in a centrifuge with the tubes closed with self-sealing stoppers, providing a partial vacuum in the upper tube, rotating the tubes at high speed about an axis parallel to and spaced from the axis of the tubes and needle, after separation of the red blood cells from the plasma and serum causing the tubes while still being rotated to be moved relative to one another such as to cause the needle to enter both tubes through the stoppers, separating the tubes while still being rotated by the centrifuge whereby to remove the needle from both tubes.

Abstract: Red cells are separated from plasma or serum of whole blood by arranging an evacuated tube sealed by a self-sealing stopper above and preferably coaxial with a tube containing a blood sample and sealed by a self-sealing stopper. A hollow double ended needle is held by a fixture and is disposed between and coaxial with the tubes and the tubes are placed in the fixture in a vertical position in a centrifuge and rotated about and spaced from an axis parallel to the axis of the tubes and needle. After the red cells are separated from the serum and/or plasma the tubes are pushed toward one another so that the needle penetrates both stoppers and the serum and/or plasma is drawn into the upper tube. The tubes and needle are separated while still being rotated so that the whole blood components are separated as required.