Abstract: The invention relates to a method and a blood bag system for the separation of blood components from whole blood, the blood being tapped into a blood bag, which is then centrifugated to form an upper layer containing blood plasma, a lower layer containing red blood cells and an intermediate buffy coat layer, and it is characterized in that the blood is tapped into a first blood bag (1,28) having outlets both at the top (7,30) and at the bottom (1,33), and that after centrifugation the layer containing blood plasma is pressed out through the upper outlet (7,30) of the blood bag while the layer containing red blood cells is pressed out through the lower outlet port (10,33) of the blood bag, so that substantially only the intermediate layer remains in the bag (1,28).

Abstract: The invention relates to a device for blood separation by squeezing out blood components from a blood bag (29) having at least one outlet conduit (30), said device comprising a support surface (1) and a pressure surface (3) being movable relatively to the support surface and arranged for compressing a blood bag (29) inserted between the pressure surface (3) and the support surface (1). The pressure surface (3) is arranged essentially in parallel with the support surface (1) and drive means are provided for displacement of the pressure surface (3) substantially perpendicularly to the support surface (1) for compressing the blood bag (29) essentially uniformly over the entire surface thereof, and it is provided with at least one sensing device (17, 18), which is arranged to detect when a pre-selected blood component layer has reached a given level in the blood bag (29) and in response thereto to activate means (20) for shutting-off at least one of said outlet conduits (30).