Eupergit C-coated membranes as solid support for a sensitive immunoassay of human albumin

A number of commercially available membranes preactivated by coating with oxirane-containing Eupergit C beads were used for diagnostic immunoassay applications. These membranes possess a higher capacity for protein binding than the respective unmodified membranes as measured with fluorescently labelled antibodies. Immobilization of antigens or antibodies as the first step of the assay was achieved by covalent binding of amino groups of proteins to the oxirane moieties introduced onto the membranes. The high performance of the newly developed membranes bearing covalently bound antibodies, was demonstrated by a dot enzyme-linked microalbuminuria immunoassay as compared to unmodified membranes.