A container for use in batch treatment of a liquid, particularly blood, such as centrifugal separation of blood into fractions of different densities and/or for washing blood cells suspended in a liquid, comprises walls of flexible sheet material which define between them a closed compartment for holding a quantity of liquid and a conduit which communicates with the compartment. The conduit is adapted to be acted on by a peristaltic pump for moving liquid through the conduit to or from the compartment or alternatively the conduit prevent liquid flow through the conduit.

A substantially enclosed centrifuge tube having a small fill or access port at one end. In its preferred form there is integrally formed adjacent the fill port a neck or stem which is fused to hermetically seal the centrifuge tube to provide a permanent and complete seal of the centrifuge tube. A plug is securely mounted within the centrifuge rotor above the centrifuge tube when placed in the rotor to provide solid support adjacent the complete exterior surface of the tube. The interior of the plug is shaped to conform and mate with the upper end of the centrifuge tube. The use of a removable capping means placed on the centrifuge tube is eliminated. Access to the tube subsequent to the centrifugation run requires puncturing or cutting of the tube.

A fluid container particularly useful in a centrifuge system for separating the various fractions in blood. The container comprises two circular sheets of flexible material, having central openings therein. The outer peripheral edges are sealed together, as well as annular-like portions extending outwardly from the central opening. Concentric-like inner and outer annular-like channels are thus formed at the outer peripheral portion of the assembly. Radial arcuate portions are sealed off, thereby providing interrupted annular-like channels. At a first end of the inner annular-like channels, an inlet tube is provided, extending outwardly from the central opening and communicating with the first end of the inner annular-like channel. At the outlet or second end of the inner annular-like channel, there is provided a radially extending inter-channel connector, which comprises a sealed off portion extending between the adjacent ends of the inner and outer annular-like channels. Also at this outlet end of the inner channel, a radially enlarged region is provided, acting as a first collecting chamber, into which an outlet tube is sealed, extending from the inner opening. A second collection chamber is provided at the outlet end of the outer annular-like channel. A plurality of outlet tubes extend radially outward from the center of the bag to open within the second collection chamber at different radial distances. Through these outlet tubes, selected separated portions of the fluid are withdrawn from the bag.

Improved, flexible, collapsible containers are provided for the storage of frozen blood and the like at cryogenic temperatures. The containers are defined by plastic walls consisting essentially of a biaxially-oriented ethylene-vinyl acetate copolymer containing from ten to thirty-five percent by weight of vinyl acetate units. The container wall thickness is typically from 0.01 to 0.025 inch.

A centrifuge rotor for use in the continuous separation of a liquid into fractions has a recess for receiving a flow-through separation container. The recess has interrupted annular shape with inclined side-walls. The inclination of the sidewalls and the cross-sectional area of the recess increase continuously in the circumferential direction from one end of the recess to the other. A collapsible flow-through separation container having flexible inlet and outlet tubes is adapted to fit within the rotor recess. Its cross-sectional area increases continuously from the inlet end to the outlet end.