with a release solution the monomeric solution can be prepared in deionized water with ethanol to improve solubility or other conventional solvent if cast by itself the polymer is formed by drying at from 50 u00b0 150 u00b0 c for a period of about 15 minutes as noted above the polymer may be used as the membrane alone or as a coating on other supports to lend stability to the polymer the only requirements the support must meet is that it be suitable for use in the physical manipulations of the assay and be inert with respect to the elements of the assay glass plates inert polymers and the like may be acceptable supports for overcoating with the polymer of the invention alternatively these quaternary polymers and copolymers can be coated as a single layer from an admixture with nylon pvdf nitrocellulose and other polymeric binders in one preferred embodiment membranes already established as suitable for use in blotting assays such as nylon membranes pvdf and in particular nitrocellulose membranes can function as the support overcoated with the polymer of the invention to overcoat a substrate the polymer solution is deposited on the membrane strip and rolled across the surface of the membrane with e g rubber tubing to provide a uniform coating over.