Abstract: A reusable apparatus for multiphase, multistage countercurrent liquid separation is presented. The apparatus is particular useful in progressive multistage separation of target microorganisms from background organisms and materials with precise transfer, air exclusion, homogeneous mixing, isolation from the ambient atmosphere, in the absence of valves and at ow cost. The structure has at least one chamber in which a piston-like sliding bottom is sealingly moved or braked and includes internal structure for mixing, preferably a magnetic-stainless steel ball which can be reciprocated from the outside to mix the liquid contents. Motion of the bottom is limited by stops. A number of ways to actuate the apparatus are taught.

Abstract: A valve particularly adapted for use as a sterilizable drain valve to be mounted flush in the bottom of a tank, has a housing body running flush with the bottom of the tank and a piston-mounted diaphragm sealing an opening perpendicular to the tank walls. A steam inlet and first outlet, running perpendicular to the valve axis, communicate with a valve chamber through which the piston operator and diaphragm are movable. The diaphragm can be polyetheretherketone (PEEK), which is difficult to imprint, at least on a side facing the opening in the tank. A containment outlet disposed opposite the diaphragm from the inlet permits containment of tank contents in the event of diaphragm rupture. The containment outlet is connected to the area of the diaphragm adjacent the pump chamber along an axial slot in the operator piston. A handle threadably mounted on a bonnet of the valve housing is used for axially displacing the operator pistor toward and away from the inlet.