Method for separating cell culture mixture

A method for separating a cell culture mixture comprising the steps of:

• a) providing a centrifugal separator comprising a stationary frame;
• a rotatable assembly;
• and a drive unit for rotating the rotatable assembly relative the frame around an axis of rotation, wherein the rotatable assembly comprises a rotor casing enclosing a separation space in which a stack of separation discs is arranged to rotate around a vertical axis of rotation, said rotor casing further comprising a mechanically hermetically sealed inlet for supply of said cell culture mixture to said separation space;
• a first mechanically hermetically sealed liquid outlet for discharge of a separated liquid phase and a second mechanically hermetically sealed liquid outlet for discharge of a separated cell phase, said cell phase having a density that is higher than said liquid phase, wherein said hermetically sealed inlet is arranged at a first axial end of said rotor casing and arranged so that the cell culture mixture to be separated enters said rotor casing at the rotational axis, and wherein said second mechanically hermetically sealed outlet is arranged at a second axial end of said rotor casing opposite said first end and arranged so that said separated cell phase is discharged at the rotational axis;
• b) supplying said cell culture mixture to be separated to said inlet;
• and
• c) discharging a separated cell phase via said second mechanically hermetically sealed liquid outlet and a liquid phase via said first hermetically sealed liquid outlet.