Abstract: The present invention provides a positively charged microporous membrane having a protein binding capacity about 25 mg/ml or greater comprising a hydrophilic porous substrate and a crosslinked coating that provides a fixed positive charge to the membrane. The present invention further provides a positively charged microporous membrane comprising a porous substrate and a crosslinked coating comprising pendant cationic groups. The membranes of the present invention find use in a variety of applications including ion-exchange chromatography, macromolecular transfer, as well as detection, filtration and purification of biomolecules such as proteins, nucleic acids, endotoxins, and the like.

Abstract: Disclosed is a method for processing a plasmid-containing fluid comprising contacting the plasmid-containing fluid with two charged membranes and obtaining a plasmid-enriched fluid such as a purified plasmid. In an embodiment, the first charged membrane is positively charged, and the second charged membranes is positively or negatively charged membrane. In a preferred embodiment, both first and second charged membranes are positively charged. In another embodiment, the plasmid-containing fluid is contacted with two positively charged membranes and a third charged membrane. The present invention further provides a system and a kit for processing plasmid-containing fluids.

Abstract: The present invention provides a membrane comprising (a) polymer solids comprising 60 wt. % or more of a fully synthetic organic polymer and optionally about 40 wt. % or less of a polymer of natural origin and (b) a cellulose compound which allows for the detection of a biological molecule of interest, wherein the cellulose compound is uniformly distributed throughout the surface of the membrane. The present invention also provides methods of preparing and using such membranes.