Patent ID: 7279339

Claim:
A reagent kit for an immunoassay of a target substance existing in a free form and a bound form in a specimen, comprising a reagent for the immunoassay comprising a first latex particle (1) which is immobilized with a first monoclonal antibody (1) for the target substance, and a second latex particle (2) which has a different mean particle size from the first latex particle (1) and is immobilized with a second monoclonal antibody (2) having a different recognition site for the target substance from the first monoclonal antibody (1), and a reagent for an agglutination accelerator, which accelerates an agglutination reaction between the first and second monoclonal antibodies and the target substance, comprising a copolymer obtained by polymerizing: a monomer represented by the following general formula: [2]: (wherein, R1-R3 are each independently a hydrogen atom or an alkyl group optionally having a hydroxyl group; R4 is an alkylene group; R5 is an alkylene group optionally having a substituent and optionally having an oxygen atom in the chain; R6 is a hydrogen atom or a methyl group; and X is an oxygen atom or a —NH-group), and benzyl methacrylate.