Modified filter membrane and the use thereof

Kit for testing blood plasma, comprising a filter with a filter membrane surface-coated with a modifying agent for separating blood plasma and blood serum from a blood sample, wherein the modifying reagent is a hydrogel former and is a poly(hydroxyethyl) methacrylate or a copolymer of 2-hydroxyethyl methacrylate,

• wherein the surface is coated by treating the surface with a solution or dispersion of the modifying reagent, that contains the modifying reagent in quantities of 1 to 3 wt. %, based on the solution or dispersion, for a period of 30 minutes to 5 hours,
• wherein the filter membrane is a porous asymmetrical membrane,
• wherein the material of the filter membrane comprises a polymer from among the following polymers:
• polyamide, polyethylene terephthalate, polysulfone, polyether sulfone, polyvinyl pyrrolidone, polyurethane, polyacrylonitrile, poly(vinylidene fluoride), polytetrafluoroethylene, polyacrylonitrile-methacrylate copolymer, cellulose, modified cellulose, cellulose ether and mixtures and copolymers thereof, and
• wherein the filter comprises a filter upper part and a filter lower part, the filter lower part having a convex curvature,
• the kit further comprising a cartridge, wherein the cartridge comprises a main body having a plurality of channels and cavities, including a receiving cavity, wherein the cartridge comprises a cover for the channels and cavities, and wherein the cartridge has a connection for connecting an outlet of the filter to the receiving cavity of the cartridge.