A description is given of a mobile system for separating donor blood by means of gravitational force into erythrocyte concentrate and plasma. This mobile system comprises a first bag (1), serving as a reservoir for the blood to be separated, and at least a second bag (4) and a third bag (5) for respectively receiving erythrocyte concentrate and plasma, and also a number of tubes for connecting the flexible bags consisting of plastics material to a separator module having a separating membrane in the form of a bundle of hollow fibres, and this system is distinguished by the fact that the system is divided into at least a first and a second sterile-packed, individual subsystem, that the at least one first subsystem comprises the individual bags and associated connecting tubes and the second subsystem comprises the separator module, and that, for the sterile or at least virtually sterile connection of the tubes to the separator module, male/female connectors (8, 10), in particular Luer-Lock connectors, are provided, one part of which is respectively fixed or integrated in the housing of the separator module and the complementary part of which is connected to the end of the respective tube.
