The hand that rocks the cradle

The invention provides a container assembly for use in conjunction with centrifuges of the normal or axial type. The assembly includes a pair of telescopically engageable containers in fluid communication via a conduit extending coaxially from the base of the outer container through the base of the inner container. Component phases of a fluid mixture within the inner container may be separated by withdrawing the inner container from the outer container until the conduit opening communicates with the appropriate component phase, and fluid is permitted to flow through the conduit into the outer container.