Abstract: A centrifuge system, especially for centrifugation of pathologically dangerous material, is characterized by a centrifuge head adapted to contain a carrier liquid and so formed and shaped that upon rotation of the head about its axis of symmetry the carrier liquid is distributed in a configuration to support one or more sealed sample containers wholly by floatation. The distribution of the carrier liquid in the rotating head may be as an annular body of constant cross section, or as two or more bodies accommodated in fluidly linked chambers in the head. The sample containers may be rigid and for instance tubular, or flexible and for instance bag-like.