An apparatus for centrifuging and furthermore automatically handling a container (10) for separating a component, such as fibrin monomer, from plasma, where the container (10) comprises a cylindrical member (11) with a lower rim as well as a piston member (12) with a tubular piston rod (12) projecting upwardly from the upper end of the cylindrical member (11). The apparatus comprises a supporting turntable (1) with a first gripping member (27) releasably gripping the lower rim of the cylindrical member (11) when the container is placed thereon, the supporting turntable being connected to a first activator (5) for rotating the turntable (1) with the container (10) about the central axis thereof. Furthermore, the apparatus comprises a rotatably journalled piston activating mechanism adapted to activate the piston (12) by way of a second activator (21) and provided with a second gripping member (13) for releasably gripping the piston rod (12). The first gripping member (27) is adapted to automatically enter a locking engagement with the inner side of the cylindrical member (11) independent of the rotating position of the container (10) relative to the supporting turntable (1) and upon activation of a third activator (8) when the container (10) is placed on the supporting turntable (1). The second gripping member (13) is adapted to succeedingly and automatically enter a locking engagement with the piston rod (12) upon activation of a fourth activator (15).