Abstract: A separating tube (2) preferably made from a plastics material for centrifugal separation of a liquid containing at least two components and preferably blood is provided, in which an asymmetrically shaped separating member (6) serves to separate the two components. The separating member (6) has a specific gravity between that of the two components to be separated. As a result of the asymmetrical shape, the center of gravity (S) of separating member (6) is eccentrically positioned with respect to axis (M) of separating tube (2), so that the separating member (6) is rotated or tilted during centrifuging. At least one gap (f) is formed through which one of the two components reaches the top of separating member (6). At the end of the centrifuging process, the bouyancy of the heavier component rotates separating member (6) back into its original position in which it seals off separating tube (2). FIG. 4 is intended for publication with the summary.