Sepn. assembly for fluids, esp. tiny fractions of blood - including a sepg. filter piston which slides into lower tube to form a fluid seal

摘要

The assembly consists of a lower cylindrical tube and an upper sepg. filter piston which slides into the tube forming a fluid seal. The novelty is that (a) the sepg. filter piston has a filter area and a valve, above which is a bush whose external dia., is about the same as that of the internal dia., of th tube; (b) the insert, which is pushed in the bush at the base of the piston shaft, is friction tight with the sepg. filter piston; (c) the friction tightness is weaker than the sliding fit between the piston and the tube; and (d) when the piston is slid into the tube, the upper shaft and contents and insert can be pulled away from the lower piston. USE/ADVANTAGE - It is claimed that the arrangement facilitates the almost complete removal of even small quantities of blood serum from the upper sector of the sepn. tube.