The present invention relates to a receptacle (20) intended to receive a bag system (1) for the treatment of the blood, comprising a primary blood bag (2) in fluidic communication with at least one satellite bag (3,5), said receptacle comprising a cavity (21) having a bottom (22) and a lateral wall (23), said cavity being divided by a pressing plate (24) in a primary compartment (25) intended to receive the primary blood bag (2) and a secondary compartment (26) intended to receive at least one satellite bag (3,5), respectively, the pressing plate (24) is arranged to be able to move inside said cavity (21) in a first direction towards the said lateral wall (23) so as to compress the primary blood bag (2).
