Abstract: A porous membrane is formed from an interpenetrating polymer network of a hydrophobic polymer and a polymerized and crosslinked hydrophilic monomeric composition. A solution of the polymer and monomeric composition is cast, exposed to ultraviolet radiation, coagulated and dried. The resulting dried membrane is annealed in order to render its surface hydrophilic.

Abstract: A filter punch construction is provided for use in conjunction with a multiwell filtration device wherein each well includes a filtration membrane. The punch has a leading flat surface to which is secured an elongated piercing member having a sharp point and a following surface to which is secured a guide member. The piercing member pierces the filtration membrane in each well and the flat leading surface pushes the entire membrane and retentate thereon into a receptacle vial.

Abstract: A gamma radiation sterilized membrane laminate is provided comprising a porous polytetrafluoroethylene membrane directly laminated to a porous polyester web substrate. The laminate is hydrophobic and has a burst strength when unsupported of at least 10 psi in both the forward and reverse direction of filtration after the laminate is exposed to radiation.

Abstract: A composite, porous membrane is formed from a porous polymer membrane having desired bulk properties on which is directly coated a cell attachment and/or growth promoting composition and a cross-linked polymer having desired surface properties. The composite membrane retains the porosity of the porous polymeric membrane. In one embodiment, when the substrate is polytetrafluoroethylene the composite is microscopically transparent.

Abstract: A process is provided for purifying potable water to produce American Association for Advancement of Medical Instrumentation (AAMI) standard water for dialysis, United States Pharmacopeia Convention, Inc. USP XXII specifications water for injection or sterile water for injection. Potable water is passed through a plurality of treatment steps including a preliminary filtration step, a carbon adsorption module and a reverse osmosis module to produce water to the quality specified by AAMI for hemodialysis. An ion exchange filtration step is added to the steps stated above to produce USP XXII quality specifications for water for injection and a disposable sterilizing microfilter is further added to all the steps stated above to produce sterile water for injection.

Abstract: Microporous or open ultrafiltration poly (tetrafluoroethylene-co-perfluoro-(alkyl vinyl ether)) (PFA) or poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP) film membrane or hollow fibers having open pores are formed from a melt blend of 10 to 35 weight percent of the PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and one or more surfaces of the shaped melt blend are coated with the solvent prior to phase separation of the melt blend. Coating the membrane with solvent during shaping results in membrane having larger pores on that membrane surface as compared to membranes not coated with solvent. The shaped melt blend is cooled to effect phase separation and crystallization of the PFA or FEP from the blend. The solvent is separated from the PFA or FEP by extraction and the porous PFA or FEP is heat set under restraint to prevent shrinkage.

Abstract: A composite membrane and process utilizing the membrane which is capable of selectively removing particles such as viral particles from a solution such as a protein solution is provided. The membrane comprises a porous membrane substrate, a surface skin having ultrafiltration separation properties and an intermediate porous zone between the substrate and the skin which intermediate zone has an average pore size smaller than that of the substrate. The intermediate zone is free of voids which break the skin and which directly fluid communicate with the substrate. The composite is capable of a log reduction value of at least 3 (99.9% removal) of particles selectively from solution.

Abstract: A filtration apparatus is provided comprising a multiwell plate wherein each of the wells in the plate has a filter membrane bonded to the entire peripheral surface of an opening of the well. The filter membrane has a tab which permits removing the filter membranes from the wells without rupturing the membrane.

Abstract: Microporous or open ultrafiltration poly (tetrafluoroethylene-co-perfluoro-(alkyl vinyl ether)) (PFA) or poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP) film membrane or hollow fibers having open pores are formed from a melt blend of 10 to 35 weight percent of the PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and one or more surfaces of the shaped melt blend are coated with the solvent prior to phase separation of the melt blend. Coating the membrane with solvent during shaping results in membrane having larger pores on that membrane surface as compared to membranes not coated with solvent. The shaped melt blend is cooled to effect phase separation and crystallization of the PFA or FEP from the blend. The solvent is separated from the PFA or FEP by extraction and the porous PFA or FEP is heat set under restraint to prevent shrinkage.

Abstract: A filter punch construction is provided for use in conjunction with a multiwell filtration device wherein each well includes a filtration membrane. The punch has a leading flat surface to which is secured an elongated piercing member having a sharp point and a following surface to which is secured a guide member. The piercing member pierces the filtration membrane in each well and the flat leading surface pushes the entire membrane and retentate thereon into a receptacle vial.

Abstract: An apparatus and process are provided for transferring a gel shaped as a cylinder containing a treated sample from a first step to a second electrophoresis step without distorting the position of the treated sample within the shaped gel. A shaped gel useful in electrophoresis is formed in a tube with a multifilament thread extending the entire length of and within the central portion of the shaped gel. The shaped gel then is employed in a first treatment step to form a treated sample that may be a separated sample. After extrusion of the gel from the tube, the portion of the thread extending from each end of the shaped gel is grasped and the shaped gel containing the treated sample is transferred to contact a slab gel along the entire length of the shaped gel to effect an electrophoresis step in the second treatment step.

Abstract: An electrodeionization apparatus and process are provided for removing ions from liquids. Liquid to be purified is passed through depleting compartments containing mixed anion and cation exchange resin beads while a second liquid is passed through concentrating compartments also containing ion exchange resin beads. Ions, under influence of a D.C. potential, pass from the depleting compartments into the concentrating compartments through ion permeable membranes. The beads in the depleting compartments are housed within subcompartments of controlled width and thickness and are retained therein by the ion permeable membranes which are secured to the walls of the subcompartments. Means are provided for reversing the polarity of the D.C. potential to convert the depleting compartments to concentrating compartments and the concentrating compartments to depleting compartments. Means are provided for continuously recovering purified water from the apparatus regardless of the polarity of the D.C.

Abstract: A device for the production of ultrapure water comprising tubes containing water treatment elements joined by two end plates. Grids are disposed between the tubes and the end plates to retain resin or carbon particles. Connector terminations provide a hydraulic connection between a control unit and the tubes. The filter is mounted in the tubes by means of an adapter which also provides a seal between inlet and outlet sides of the filter. Holes are provided in the connector terminations and the end plates to enable selection of the path of fluid in the water treatment elements.

Abstract: A composite porous membrane is formed from a porous polymeric membrane having desired bulk properties on which is directly coated a cross-linked polymer having desired surface properties. The composite membrane retains the porosity of the porous polymeric membrane. The cross-linked surface polymer is produced from a crosslinkable monomer or polymer by energy from an electron beam in the absence of a chemical polymerization initiator.

Abstract: An electrodeionization apparatus is provided for removing ions from liquids. Liquid to be purified is passed through at least two ion depletion compartments containing mixed anion and cation exchange resin beads in a given separation stage. A second liquid is passed through concentration compartments free of ion exchange resin beads. Ions under the influence of D.C. potential pass from the depletion compartments into the concentration compartments through ion permeable membranes. The beads in the depletion compartments are housed within subcompartments of controlled width and thickness and are retained therein by the ion permeable membranes which are secured to the walls of the subcompartments.

Abstract: An electrodeionization apparatus and process are provided for removing ions from liquids. Liquid to be purified is passed through depleting compartments containing mixed anion and cation exchange resin beads while a second liquid is passed through concentrating compartments free of ion exchange resin beads. Ions, under influence of a D.C. potential, pass from the depleting compartments into the concentrating compartments through ion permeable membranes. The beads in the depleting compartments are housed within subcompartments of controlled width and thickness and are retained therein by the ion permeable membranes which are secured to the wall of the subcompartments.

Abstract: A composite, microscopically transparent, porous membrane is formed from a porous polytetrafluoroethylene membrane having desired bulk properties on which is directly coated a cross-linked polymer having desired surface properties. The composite membrane retains the porosity of the porous polymeric membrane.

Abstract: A container for one or more micro-organism culture mediums has a substantially cylindrical or frustoconical casing open at both ends. A transverse perforated support grid is joined to an inside wall of the casing at its circular edge. A base is fitted to a lower end of the casing and a lid is fitted in a liquid-tight manner onto the upper end of the casing. A culture medium at a raised temperature can thus be poured into the container while it is resting upside down on its lid with the base removed.

Abstract: A composite, microscopically transparent, porous membrane is formed from a porous polytetrafluoroethylene membrane having desired bulk properties on which is directly coated a cross-linked polymer having desired surface properties. The composite membrane retains the porosity of the porous polymeric membrane.

Abstract: Microporous poly (tetrafluoroethylene-co-perfluoro (alkyl vinyl ether)) (PFA) or poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) membrane or hollow fibers are formed from a melt blend of 10 to 35 weight percent of PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and cooled to effect phase separation of the PFA or FEP from the blend. The solvent is removed from the PFA or FEP by extraction and the porous PFA or FEP is dried under restraint to prevent shrinkage.