Abstract: The syringe (10) comprises a detachable syringe barrel (14) connected to a housing (12). The housing contains a drive means connected to a plunger (24). The drive means is for extending and retracting the plunger into and out of the detachable syringe barrel. The detachable syringe barrel comprises a stopper (26) at one end thereof in sealing engagement with the interior of the barrel and for releasable engagement with the end of the plunger distal to the drive means. At least a portion of the stopper is flexible between a first position and a second position. In the first position, the flexible stopper may be disengaged from the plunger upon retraction of the plunger away from the detachable syringe barrel. In the second position, the flexible stopper is maybe engaged with the plunger upon extension of the plunger toward the detachable syringe barrel.