Substrate for immunoassay and means of preparing same

In a method for the preparation of an activated solid phase substrate for use in immunoassay procedures, the steps which comprise treating a dry microporous filter membrane formed of a solid polymeric methanol-swellable material which includes esterified hydroxy groups in its chemical structure with an anhydrous organic solvent containing methanol to swell the polymeric structure, hydrolyzing at least some of the ester groups present and converting at least some of the hydroxy groups thus made available to the alkali metal hydroxylate form, reacting the alkali metal hydroxylate groups on said polymeric material with trichlorotriazine, and then removing any residual organic solvent from the solid polymeric reaction product.

In a method for the preparation of an activated solid phase substrate for use in immunoassay procedures, the steps which comprise treating a dry microporous filter membrane having a cellulose ester base with an anhydrous organic solvent containing methanol to swell the cellulose ester base material, reacting the swollen cellulose ester base material with sodium methoxide to hydrolyze at least some of the ester groups present and convert some of the free hydroxy groups thus made available to the sodium hydroxylate form, reacting the sodium hydroxylate groups on said cellulose ester with trichlorotriazine, and then removing any residual organic solvent from the solid reaction product.