Abstract: The present invention provides a reagent for an immunoassay comprising insoluble carrier particles which can give the values to be determined with high accuracy and reliability, and can be stored for a long time; an immunoassay using the reagent; and a method for keeping the reagent stable.

Abstract: The present invention provides a reagent for an immunoassay comprising insoluble carrier particles which can give the values to be determined with high accuracy and reliability, and can be stored for a long time; an immunoassay using the reagent; and a method for keeping the reagent stable.

Abstract: The present invention provides an agglutination immunoassay, wherein the agglutination of insoluble carrier particles such as latex are stabilized and uniformized to give good reproducibility, and a reagent therefor. In the agglutination immunoassay which comprises allowing an antigenic substance in a sample to bind to insoluble carrier particles carrying substantially neither antigens nor antibodies thereon, and allowing an antibody or an antibody complex which reacts specifically to the antigenic substance to bind to the antigenic substance to give a selective agglutination of the insoluble carrier particles, a homopolymer prepared by polymerization of a monomer such as 2-methacryloyloxyethyl phosphorylcholine having a phosphorylcholine group and a vinyl group, or a copolymer prepared by polymerization of a monomer having a phosphorylcholine group and a vinyl group, with a monomer having a vinyl group such as n-butyl methacrylate is used.

Abstract: The present invention provides a reagent for an immunoassay comprising insoluble carrier particles which can give the values to be determined with high accuracy and reliability, and can be stored for a long time; an immunoassay using the reagent; and a method for keeping the reagent stable.

Abstract: The present invention provides an agglutination immunoassay, wherein the agglutination of insoluble carrier particles such as latex are stabilized and uniformized to give good reproducibility, and a reagent therefor. In the agglutination immunoassay which comprises allowing an antigenic substance in a sample to bind to insoluble carrier particles carrying substantially neither antigens nor antibodies thereon, and allowing an antibody or an antibody complex which reacts specifically to the antigenic substance to bind to the antigenic substance to give a selective agglutination of the insoluble carrier particles, a homopolymer prepared by polymerization of a monomer such as 2-methacryloyloxyethyl phosphorylcholine having a phosphorylcholine group and a vinyl group, or a copolymer prepared by polymerization of a monomer having a phosphorylcholine group and a vinyl group, with a monomer having a vinyl group such as n-butyl methacrylate is used.

Abstract: The present invention provides: a reagent and a kit for an insoluble carrier particle nephelometric immunoassay which stabilize the agglutination reaction by suppressing the action of blood plasma components that are involved in the agglutination reaction of insoluble carrier particles such as latex and affect the values to be determined, to provide the stable absorbances of the reaction solutions and the accurate determination results; and a method of an insoluble carrier particle nephelometric immunoassay utilizing said reagent or kit.

Abstract: Disclosed are a method for quantitative determination of bilirubin and a reagent for the method, which are useful in clinical examinations. The method comprises subjecting the bilirubin in a sample to coexist with ascorbate oxidase and a reaction promoter in aqueous medium to thereby oxidize the bilirubin, measuring the change in absorbance of the aqueous medium and comparing the change in absorbance with a calibration curve. The reagent comprises ascorbate oxidase and a reaction promoter.

Abstract: The present invention relates to a method of quantitative determination of sodium ions in a sample using .beta.-galactosidase, wherein the .beta.-galactosidase reaction is conducted in the presence of at least one chelating agent selected from of 1,2-cyclohexanediamine-N,N,N',N'-tetraacetic acid, ethylenediamine-tetraacetic acid, triethylenetetranine-hexaacetic acid, diethylenetriamine-N,N,N',N",N"-pentaacetic acid, 1,3 -diminopropan-2-ol-N,N',N'-tetraacetic acid, ethylenediamine-N,N'-dipropionic acid dihydrochloride, ethylenediamine-tetrakis(methylenesulfonic acid), iminodiacetic acid, hydroxyimino-diacetic acid and nitrilotriacetic acid.The method of quantitative determination of sodium ions of the present invention is useful in clinical examinations and the accuracy in the measurement by the method is high.