Abstract: A generally cylindrical, open topped, container for use in a centrifuge instrument has a seal ring disposed in a circumferentially extending groove provided on the interior surface of the container. At least one generally axially extending channel is formed in the interior surface of the container with a first end of the channel communicating with the groove. The intersection of the channel with the groove exposes a portion of the seal ring whereby an implement, such as the tingemail of an operator, may engage the seal ring, thereby to facilitate the removal of the seal ring from the groove.

Abstract: A rotor identification system uses the windage of a rotor to produce a signal representative of rotor identity. For a low windage rotor the actual velocity at a predetermined measurement time is used to generate the rotor identity signal. For a high windage rotor the time needed to reach a predetermined measurement velocity is used to generate the rotor identity signal. A selector determines initially whether the rotor is within the low windage or the high windage regime.

Abstract: A centrifuge rotor has a continuous annular groove disposed radially outwardly of each of the sample receiving cavities provided in the rotor. The groove collects any liquid spilled during operation of the rotor thereby to prevent the liquid from draining into the cavities and contaminating the same as the rotor slows.

Abstract: A centrifuge rotor is provided with a pair of projections frangibly connected thereto. As the rotor reaches a predetermined speed the projections simultaneously fracture forming projectiles which puncture the evacuated chamber in which the rotor is mounted. Ambient air is drawn into the chamber, thereby windage limiting the speed of the rotor. The projections are each sized and positioned to impart a total unbalance less than the multiplication product of 0.5 gram-inches times the weight of the rotor.

Abstract: A cell washing apparatus having a pivotally movable sample tube holder provided with a radially inwardly directed arm having a grasping hook thereon. The hook engages a retaining surface disposed radially inwardly of the pivot point of the holder to restrain radial outward movement of the sample tube holder.

Abstract: A centrifuge rotor has vertically oriented peripheral cavities and/or adaptors configured to receive sample containers each having a length which exceeds its diamter. Each cavity and/or adaptor is provided with a cap and/or an adaptor cap which together provide a rigid support and seal for each sample container. With this apparatus the separation gradient reorients from horizontal during separation to vertical during sample removal providing the advantages of reduced separation time and improved resolution.