The blood sampling device comprises a relatively flexible inner tube (11) and an outer tube (10). There is an annular gap (12) between the two tubes. At its front end the inner tube (11) has a front wall (30) which presses against the annular protuberance (43) of a front wall (13) of the outer tube. For mutual fixation of inner and outer tube, an engagement profile is provided on the edge of the front wall (30) of the inner tube and engages in locking fashion with a counter-profile of the outer tube. On centrifugation, the inwardly directed protuberance becomes buried in the soft material of the front wall (30) of the inner tube. This prevents liquid from reaching the annular gap (12) on centrifugation. <IMAGE>
