Patent ID: 7008532

Claim:
A chromatographic device comprising: a chromatographic tube comprising first and second opposite ends, and an inner surface, the inner surface of the tube at least in part defining an intermediate region, the intermediate region being generally between the first and second ends; a chromatographic medium within the intermediate region; a piston assembly within the tube and positioned generally between the first end of the tube and the chromatographic medium, the piston assembly defining a passage for flow of process fluid, the chromatographic medium being generally between the piston assembly and the second end of the tube; an elongate rod comprising an elongate bore, the rod extending partially into the chromatographic tube such that the piston assembly is between the elongate rod and the second end of the chromatographic tube, the elongate rod having a threaded outer surface; a threaded member threaded to the threaded outer surface of the elongate rod, the threaded member being operatively secured to the chromatographic tube.