Abstract: The present invention relates to latex particles for measurement reagents, said latex particles having a coefficient of variation in particle diameters of 10% or less and an average particle diameter of 250 to 1000 nm. Each of the latex particles contains 20% by weight or more of a compound having a refractive index of 1.60 or more. The depth of a supernatant is 5 mm or less when a liquid dispersion having a solid matter concentration of 1% by weight, which is prepared by dispersing the latex particles in ultrapure water, is placed in a tubular 10-ml measuring cylinder having a body inner diameter of 10.8 mm and is then allowed to leave for 10 days. According to the particles, a measurement of a measurement sample can be performed at a high sensitivity even when the concentration of a substance to be tested in the measurement sample is low.

Abstract: Disclosed is a sensitized magnetic responsive particle including: a magnetic responsive particle having a core particle and at least one magnetic layer disposed on the core particle, the magnetic layer containing microparticles of a magnetic metal and/or an oxide thereof; and a substance that specifically interacts with an analyte, the substance being supported on the magnetic responsive particle, wherein, assuming that a volume and a weight of the core particle are respectively vc and wc, and that a volume and a weight of the magnetic responsive particle are respectively ve and we, the magnetic material density [(we?wc)/(ve?vc)] satisfies the following expression 1: 2.0?(we?wc)/(ve?vc) ??Expression 1 The magnetic responsive particle has a high magnetic collection property in spite of a small particle size. When the magnetic responsive particle is used, a reagent for an immunoassay having excellent magnetic separability and capable of realizing high sensitivity can be provided.

Abstract: Disclosed is a sensitized magnetic responsive particle including: a magnetic responsive particle having a core particle and at least one magnetic layer that is disposed on the core particle and includes microparticles of a magnetic metal and/or an oxide thereof; and a substance that is supported on the magnetic responsive Particle and interacts specifically with an analyte, wherein the coefficient of variation in the weight-average particle size of the magnetic responsive particles is 15% or less. The magnetic responsive particle provided has excellent magnetic separability.

Abstract: A problem to be solved is to perform an immunoassay method for BG in a biological sample having a sensitivity equivalent to and a reactivity similar to a Limulus amebocyte lysate reagent. The problem can be solved by an immunoassay method for ?-D-glucan in a biological sample, comprising assaying ?-D-glucan in the biological sample by using a monoclonal antibody binding to (1?3)-?-D-glucan having a degree of polymerization of 4.

Abstract: There is provided a method for preventing an occurrence of an irregular detection value and performing measurement with good reproducibility in an immunoassay using an automatic analyzer regardless of whether the reaction cuvette used is of a disposable type or a reusable type and whether the optical detection method used measures transmitted light or scattered light. There is also provided an immunoassay reagent for use in the method. A method for preventing the occurrence of irregular detection and enhancing the reproducibility of measurement includes using a reagent containing polyethylene glycol or the like having a weight-average molecular weight of 300 to 3000.

Abstract: The present invention provides fluorescent particles for a diagnostic agent which contain a synthetic polymer and at least 10 mass %, on a total particle mass basis, of an aggregation-induced emission material, and have on the surface thereof a binding partner which binds with an analyte. These fluorescent particles for a diagnostic agent are non-toxic, have improved visibility and reproducibility, and support a binding partner for an analyte.

Abstract: The present invention relates to latex particles for measurement reagents, said latex particles having a coefficient of variation in particle diameters of 10% or less and an average particle diameter of 250 to 1000 nm. Each of the latex particles contains 20% by weight or more of a compound having a refractive index of 1.60 or more. The depth of a supernatant is 5 mm or less when a liquid dispersion having a solid matter concentration of 1% by weight, which is prepared by dispersing the latex particles in ultrapure water, is placed in a tubular 10-ml measuring cylinder having a body inner diameter of 10.8 mm and is then allowed to leave for 10 days. According to the particles, a measurement of a measurement sample can be performed at a high sensitivity even when the concentration of a substance to be tested in the measurement sample is low.

Abstract: This analyte concentration measuring method including: preparing a mixed solution by mixing a sample solution containing an analyte, with a solution containing aggregation-induced emission fluorescent material-containing particles that have a binding partner which binds with the analyte and that agglutinate and fluoresce when the analyte binds to the binding partner; measuring the fluorescence intensity generated from the aggregation-induced emission fluorescent material-containing particles in the mixed solution; and comparing a fluorescence intensity calibration curve for analyte concentration with the fluorescence intensity, and associating the fluorescence intensity with the analyte concentration in the mixed solution. Employing agglutinating-luminescent-material-containing particles enables measurements to be carried out with a satisfactory detection sensitivity while suppressing background fluorescence.

Abstract: Provided is a method for the simple and highly accurate assay of PSA by a one-step reaction that does not use carriers having different average grain sizes. Also provided is a reagent therefor. The PSA assay method comprises sensitizing insoluble carriers having the same average grain size within a range of greater than 0.20 ?m but 0.40 ?m or less using two types of anti-PSA monoclonal antibodies having different epitopes that are anti-PSA monoclonal antibodies that will react with both free PSA and PSA-ACT, which is a complex of free PSA and ?1-antichymotrypsin, and bringing the carriers into contact with a sample in the presence of an aggregation promoter.

Abstract: A polymer fine particle including a block copolymer having two or more segments, wherein the polymer fine particle has a microphase separated structure on a surface thereof, the number-average particle size is 50 nm to 1000 nm, and the coefficient of variation is less than 20%. The polymer fine particle permits highly sensitive assay by controlling the antigen- or antibody-immobilized state of the particle surface.

Abstract: An object of the present invention is to provide a latex particle for a measurement reagent with which highly sensitive measurement can be performed even in measuring a measurement sample containing a test substance in a dilute concentration. The preset invention relates to a latex particle for a measurement reagent including a copolymer obtained by copolymerizing a monomer mixture containing the following polymerizable monomers (a) to (c): (a) a polymerizable monomer having a phenyl group; (b) a polymerizable monomer having a phenyl group and a sulfonate; and (c) a polymerizable monomer having a naphthyl group, in an aqueous medium containing 7.5 to 25% by weight of C1-4 alcohol without using a surfactant.

Abstract: Latex particles for a particle agglutination assay, with which it is possible to carry out high-sensitivity assay while highly suppressing a non-specific reaction are disclosed. The latex particles being obtained by emulsion polymerization with a polymerizable monomer having a phenyl group, and a polymerizable monomer having a phenyl group and a sulfonate in an aqueous medium including a nonionic surfactant at a concentration of 0.005 to 0.02 wt % based on the aqueous medium, the latex particles having an average particle size of 0.005 to 1.0 ?m.

Abstract: A latex particle for high-sensitive agglutination assay and a reagent for agglutination assay including the particle are provided. The latex particle barely initiates non-specific reactions and can readily prepare diagnostic agents. A latex particle for agglutination assay including a polymerizable monomer having a phenyl group, a polymerizable monomer having a phenyl group and a salt of sulfonic acid, and a polymerizable monomer represented by Formula (1): CH2?CR1—COO(CH2CH2O)n—R2??(1) where R1 represents a hydrogen atom or a methyl group; R2 represents a hydrogen atom or a methyl group; and n is 1?n<20, wherein the density of functional groups derived from the polymerizable monomer represented by Formula (1) on the surface of the particle is 0.05 to 0.5 ?mol/m2.

Abstract: A particulate latex for high-sensitive agglutination assay that barely poses non-specific reactions and can readily prepare diagnostic reagents, and a reagent for agglutination assay including the particle are provided. A particulate latex for agglutination assay, including a first polymerizable monomer having a phenyl group, a second polymerizable monomer having a phenyl group and a salt of sulfonic acid, and a third polymerizable monomer represented by Formula (1): CH2?CR1—COOCH2CH2O(PO2)OCH2CH2—N(CH3)3??(1) where R1 represents a hydrogen atom or a methyl group, wherein the density of functional groups in the third polymerizable monomer represented by Formula (1) on the surface of the particulate latex is 0.003 to 0.05 ?mol/m2.

Abstract: Provided is a method for the simple and highly accurate assay of PSA by a one-step reaction that does not use carriers having different average grain sizes. Also provided is a reagent therefor. The PSA assay method comprises sensitizing insoluble carriers having the same average grain size within a range of greater than 0.20 nm but 0.40 nm or less using two types of anti-PSA monoclonal antibodies having different epitopes that are anti-PSA monoclonal antibodies that will react with both free PSA and PSA-ACT, which is a complex of free PSA and ?1-antichymotrypsin, and bringing the carriers into contact with a sample in the presence of an aggregation promoter.

Abstract: A particulate latex for high-sensitive agglutination assay that barely poses non-specific reactions and can readily prepare diagnostic reagents, and a reagent for agglutination assay including the particle are provided. A particulate latex for agglutination assay, including a first polymerizable monomer having a phenyl group, a second polymerizable monomer having a phenyl group and a salt of sulfonic acid, and a third polymerizable monomer represented by Formula (1): CH2?CR1—COOCH2CH2O(PO2)OCH2CH2—N(CH3)3??(1) where R1 represents a hydrogen atom or a methyl group, wherein the density of functional groups in the third polymerizable monomer represented by Formula (1) on the surface of the particulate latex is 0.003 to 0.05 ?mol/m2.

Abstract: A latex particle for high-sensitive agglutination assay and a reagent for agglutination assay including the particle are provided. The latex particle barely initiates non-specific reactions and can readily prepare diagnostic agents. A latex particle for agglutination assay including a polymerizable monomer having a phenyl group, a polymerizable monomer having a phenyl group and a salt of sulfonic acid, and a polymerizable monomer represented by Formula (1): CH2?CR1—COO(CH2CH2O)n—R2??(1) where R1 represents a hydrogen atom or a methyl group; R2 represents a hydrogen atom or a methyl group; and n is 1?n<20, wherein the density of functional groups derived from the polymerizable monomer represented by Formula (1) on the surface of the particle is 0.05 to 0.5 ?mol/m2.

Abstract: Latex particles for a particle agglutination assay, with which it is possible to carry out high-sensitivity assay while highly suppressing a non-specific reaction are disclosed. The latex particles being obtained by emulsion polymerization with a polymerizable monomer having a phenyl group, and a polymerizable monomer having a phenyl group and a sulfonate in an aqueous medium including a nonionic surfactant at a concentration of 0.005 to 0.02 wt % based on the aqueous medium, the latex particles having an average particle size of 0.005 to 1.0 ?m.

Abstract: The present invention has an object to provide an insoluble carrier for an antiphospholipid antibody detection reagent having a high reactivity. The present invention also has an object to provide an antiphospholipid antibody detection reagent, and a method of detecting an antiphospholipid antibody. The present invention directs to an insoluble carrier for an antiphospholipid antibody detection reagent, having a zeta potential of lower than ?45 mV in the case that the insoluble carrier is suspended in a 20 mmol/L aqueous sodium phosphate solution with a pH of 7.4 so that the resulting suspension has a solids concentration of 0.1%.

Abstract: Provided is a method for the simple and highly accurate assay of PSA by a one-step reaction that does not use carriers having different average grain sizes. Also provided is a reagent therefor. The PSA assay method comprises sensitizing insoluble carriers having the same average grain size within a range of greater than 0.20 ?m but 0.40 ?m or less using two types of anti-PSA monoclonal antibodies having different epitopes that are anti-PSA monoclonal antibodies that will react with both free PSA and PSA-ACT, which is a complex of free PSA and ?1-antichymotrypsin, and bringing the carriers into contact with a sample in the presence of an aggregation promoter.