A method is provided in a centrifugal blood processing system for adding replacement fluid without a dedicated peristaltic pump to blood components being returned to the donor. A disposable blood processing set for use in the method comprises a hermetically sealed set of blood bags, connecting tubes, needles or connectors, and supporting structures with a replacement fluid line coupled directly to a return reservoir without contact with an intervening pump.

A decanter centrifuge with a rotating bowl is provided with at least one solids discharge port and at least one clarified liquid discharge port and a screw conveyor disposed coaxially within the rotating bowl to be rotated in the same direction with a differential rotational speed. A feed suspension to be separated is introduced into a ring shaped space formed between the rotating bowl and the screw conveyor through a central feed pipe fixed to the end of the screw conveyor and supported in at least one bearing. The feed suspension is separated by centrifugal force into a solid phase and a liquid phase so that the solid phase is discharged from the solid discharge port and the liquid phase is discharged from a clarified liquid discharging apparatus. A sealing of the feed pipe and the bowl shaft at the feed end of the feed pipe is provided as adjacent double axial sealing. A liquid phase conduit is arranged in the bowl shaft for guiding the liquid phase outside of the bearings, and a liquid phase valve is provided outside the bearing on the side facing away from the bowl and screw. In this way the liquid phase discharge valve can be varied during operation of the decanter centrifuge by a hand wheel via a transmission or by a motor.

A decanter centrifuge with a rotating bowl is provided with at least one solids discharge port and at least one clarified liquid discharge port and a screw conveyor disposed coaxially within the rotating bowl to be rotated in the same direction with a differential rotational speed. A feed suspension to be separated is introduced into a ring shaped space formed between the rotating bowl and the screw conveyor through a central feed pipe fixed to the end of the screw conveyor and supported in at least one bearing. The feed suspension is separated by centrifugal force into a solid phase and a liquid phase so that the solid phase is discharged from the solid discharge port and the liquid phase is discharged from a clarified liquid discharging apparatus. A sealing of the feed pipe and the bowl shaft at the feed end of the feed pipe is provided as adjacent double axial sealing. A liquid phase conduit is arranged in the bowl shaft for guiding the liquid phase outside of the bearings, and a liquid phase valve is provided outside the bearing on the side facing away from the bowl and screw. In this way the liquid phase discharge valve can be varied during operation of the decanter centrifuge by a hand wheel via a transmission or by a motor.

A sample container cap is disclosed. The sample cap container includes a sample cap body capable of covering an opening of a sample container and a centrifugation status indicator device in the top of the sample cap body. The centrifugation status indicator device includes: a first substance having a first density and a first color, and a second substance having a second density and a second color. The centrifugation status indicator device displays the first substance when the sample container has been centrifuged. The first substance can be a gel, and the second substance can include a plurality of particles. The second density is higher than the first density and the second color is different from the first color.

A sample container cap is disclosed. The sample cap container includes a sample cap body capable of covering an opening of a sample container and a centrifugation status indicator device in the top of the sample cap body. The centrifugation status indicator device includes: a first substance having a first density and a first color, and a second substance having a second density and a second color. The centrifugation status indicator device displays the first substance when the sample container has been centrifuged. The first substance can be a gel, and the second substance can include a plurality of particles. The second density is higher than the first density and the second color is different from the first color.

A centrifuge tube holding assembly includes a body having a front side, a back side, a top edge, a bottom edge, a first lateral edge and a second lateral edge. The top edge has a plurality of apertures extending downwardly therein and each of the apertures may be used for removably receiving an ultracentrifuge tube. The front wall has an opening therein for viewing an open space positioned below the top edge. A panel is positioned over the opening. The panel is transparent to allow viewing through the panel. The panel has measurement indicia thereon configured to be positioned to be alignable with the ultracentrifuge tube.

A centrifuge tube holding assembly includes a body having a front side, a back side, a top edge, a bottom edge, a first lateral edge and a second lateral edge. The top edge has a plurality of apertures extending downwardly therein and each of the apertures may be used for removably receiving an ultracentrifuge tube. The front wall has an opening therein for viewing an open space positioned below the top edge. A panel is positioned over the opening. The panel is transparent to allow viewing through the panel. The panel has measurement indicia thereon configured to be positioned to be alignable with the ultracentrifuge tube.

Centrifugation systems are provided that have a non-contact seal assemblies including an upper guard and a skirted pivot, as well as a pressure source that provides a gas flow between the upper guard and a surface of the skirted pivot. In some embodiments, the non-contact seal assembly further includes a lower guard having one or more capillary channels defined on an upper surface.

A separator includes: a centrifugal drum; a drive spindle, where the drive spindle is rotatably mounted in a drive housing by a neck bearing and a foot bearing, and where the drive housing encloses a drive chamber; an electric motor which has a stator and a motor rotor, where the motor rotor is disposed on the drive spindle, where the stator is fixedly connected to the drive housing, where an air gap exists between the stator and the motor rotor, and where the stator and the motor rotor are arranged between the neck bearing and the foot bearing; a lubricating system for lubrication of the neck bearing and the foot bearing; and a coolant system; where the stator has a flange section which is disposed on a collar section of the drive housing.

A separator includes: a centrifugal drum; a drive spindle, where the drive spindle is rotatably mounted in a drive housing by a neck bearing and a foot bearing, and where the drive housing encloses a drive chamber; an electric motor which has a stator and a motor rotor, where the motor rotor is disposed on the drive spindle, where the stator is fixedly connected to the drive housing, where an air gap exists between the stator and the motor rotor, and where the stator and the motor rotor are arranged between the neck bearing and the foot bearing; a lubricating system for lubrication of the neck bearing and the foot bearing; and a coolant system; where the stator has a flange section which is disposed on a collar section of the drive housing.