Dry detection reagent containing acrylamide/styrene copolymer particles

Abstract

A dry detection reagent for detecting an immunologically active substance is prepared containing solid fine polymer particles immobilizing a substance immunologically active for the substance detected. The polymer particles are prepared by one of the following methods: a) ternary copolymerization of a monomer having carboxyl groups, a monomer having amino groups and styrene or its derivatives; b) binary copolymerization of a monomer having carboxyl groups and styrene or its derivatives, and reacting part of the carboxyl groups with a bifunctional amine such as ethylene diamine to provide amino groups; or c) copolymerizing styrene or its derivatives with a monomer having amide groups, and converting part of the amide groups to amino groups and carboxyl groups with the Hofmann reaction, or hydrolyzing part of the amide groups to form carboxyl groups. Preferably, styrene and acrylamide having amide groups are copolymerized and part of the amide groups are hydrolyzed to carboxyl groups or part of the amide groups are converted to carboxyl groups and amino groups by the Hofmann reaction. The immunologically active substance used for detecting is immobilized on the particles and the particles are dried to produce the dry reagent. To carry out detection, the dry reagent is dispersed in a liquid, the liquid is mixed with a sample containing the substance to be detected which becomes bound to the substance immobilized on the particles and the bound substance is optically detected. The dry reagent is stable during storage and has excellent re-dispersibility in a liquid.