Tube for liquid separation from solid phase - with plug and piercing piston made of plastics

摘要

A liq. collecting tube to separate a liq./solid or semisolid mixt., e.g. blood lasma or serum from the blood cell phase of centrifuged blood, consists of a plastic tube, open at both ends but with a self-sealing plug at one end. A cpd. piston which can be introduced to the same end includes a hollow piercing needle of steel or plastics which can penetrate through the plug centre. A filter in the middle of the piston permits fluid to enter through the needle into the tube cylinder, but not a solid or semisolid fraction. The pref. material for the tube is a cellulose acetobutyrate, for the plug silicone rubber end for the piston polyethylene. This is a simple and robust design which ensures a sepn. without risk of contamination.