An apparatus and a method are provided for use with a centrifuge having a rotor rotatable about an axis of rotation, the rotor including a retainer, the apparatus comprising: a separation vessel (28a) for placement in the retainer, the separation vessel including an inlet port (54a) for supplying to the separation vessel a fluid to be separated into components, a first outlet port (56a) for removing at least relatively intermediate density components of the fluid, and a second outlet port (60a) for removing at least one relatively low density component of the fluid a first line (38a) coupled to the first outlet port (56a) a second line (42b) coupled to the second outlet port (60a) and a fluid chamber (30) for separating the components of the fluid flowing through the first line, the fluid chamber being capable of being mounted on the rotor and including a fluid chamber inlet (34) fluidly coupled to the first line (38a), a fluid chamber outlet (32) in flow communication with the second line (42b) to mix the relatively low density component of the fluid with substances flowing from the fluid chamber outlet, and a fluid chamber wall extending between and defining the fluid chamber inlet and the fluid chamber outlet, the fluid chamber wall having an inner surface defining an interior.
