Abstract: A separation device adapted for separation of a wanted end product from a sample by centrifugation. According to the invention the device comprises: a first, a second and a third compartment; a first fluid connection between the first and second compartments, arranged to be opened and closed by first closing means; a second fluid connection between the second and the third compartments, arranged to be opened and closed by second closing means. The separation device is adapted to be subjected to centrifugation after having been filled with a first density gradient medium in the first compartment, sample in the third compartment and a second density gradient medium or sample in the second compartment, whereby after centrifugation the wanted end product will settle in the second compartment and the first fluid connection and the second fluid connection will be closed by the first closing means and the second closing means respectively.