Abstract: In a method of separating different density fluid components, a fluid sample is placed in a first flexible container. The container and its contents are then spun at high speed while controlling the shape of the container so that its side walls spread apart and its bottom flattens to give the container and its contents a relatively small aspect ratio whereby different density components of the fluid contents travel minimum distances while separating in the container to achieve a density distribution in the container, with the densest components of the fluid distal to the spin axis being distributed over a relatively large area surface constituted by the container bottom. The method is particularly applicable to separating different components of human blood. Various apparatus for practicing the method are also disclosed.

Abstract: Apparatus for separating or partitioning different density components of a liquid includes a liquid transfer pack composed of first and second flexible bags whose interiors are connected by tubing and a carrier for supporting the transfer pack. the carrier includes first and second sections defining first and second chambers for containing said first and second bags which sections can telescope between an extended condition wherein the volume of the second chamber is a maximum and a collapsed or retracted condition wherein the volume of the second chamber is a minimum. The two sections are biased toward their extended condition so that the first and second bags can be positioned in said chambers so that when the carrier and pack are spun at a selected high speed about an axis perpendicular to the carrier telescoping axis, the carrier sections will retract thereby maintaining the second bag in a collapsed condition in the second chamber minimum volume until the spinning slows to a selected lower speed.