Abstract: An optical-waveguide sensor chip includes an optical waveguide having a first substance immobilized on the surface thereof, the first substance being specifically reactive with an analyte substance, and fine particles dispersed on the optical waveguide and having a second substance immobilized on the surface thereof, the second substance being specifically reactive with the analyte substance.

Abstract: Provided is a technique of extracting a component in a food from the food by using a reducing agent that is inexpensive and has a mild reducing action. A component in a food is extracted by mixing the food with an extractant containing a sulfite. In addition, the resultant food extract is brought into contact with a specific antibody that specifically recognizes a substance included in a specified ingredient of interest for inspection, to thereby inspect the presence or absence and/or the amount of a specified ingredient in a food by utilizing an immunological measurement method. Further provided is a food inspection kit for inspection of the presence or absence and/or the amount of a specified ingredient in a food, including: (1) an extractant and a sulfite to be added to the extractant, or an extractant including a sulfite added; and (2) an antibody that specifically recognizes a substance included in a specified ingredient of interest for inspection.

Abstract: An optical-waveguide sensor chip includes an optical waveguide having a first substance immobilized on the surface thereof, the first substance being specifically reactive with an analyte substance, and fine particles dispersed on the optical waveguide and having a second substance immobilized on the surface thereof, the second substance being specifically reactive with the analyte substance.

Abstract: An optical-waveguide sensor chip includes an optical waveguide having a first substance immobilized on the surface thereof, the first substance being specifically reactive with an analyte substance, and fine particles dispersed on the optical waveguide and having a second substance immobilized on the surface thereof, the second substance being specifically reactive with the analyte substance.

Abstract: An optical-waveguide sensor chip includes an optical waveguide having a first substance immobilized on the surface thereof, the first substance being specifically reactive with an analyte substance, and fine particles dispersed on the optical waveguide and having a second substance immobilized on the surface thereof, the second substance being specifically reactive with the analyte substance.

Abstract: Provided is a technique of extracting a component in a food from the food by using a reducing agent that is inexpensive and has a mild reducing action. A component in a food is extracted by mixing the food with an extractant containing a sulfite. In addition, the resultant food extract is brought into contact with a specific antibody that specifically recognizes a substance included in a specified ingredient of interest for inspection, to thereby inspect the presence or absence and/or the amount of a specified ingredient in a food by utilizing an immunological measurement method. Further provided is a food inspection kit for inspection of the presence or absence and/or the amount of a specified ingredient in a food, including: (1) an extractant and a sulfite to be added to the extractant, or an extractant including a sulfite added; and (2) an antibody that specifically recognizes a substance included in a specified ingredient of interest for inspection.

Abstract: An optical-waveguide sensor chip includes an optical waveguide having a first substance immobilized on the surface thereof, the first substance being specifically reactive with an analyte substance, and fine particles dispersed on the optical waveguide and having a second substance immobilized on the surface thereof, the second substance being specifically reactive with the analyte substance.

Abstract: The method for measuring the concentration of the measuring object uses a sensor chip comprising an optical waveguide layer and an antibody immobilized layer formed on the surface of the optical waveguide layer, which comprises immobilizing the measuring object and an enzyme-labeled antibody labeled with a labeling enzyme on the antibody immobilized layer of the sensor chip having an immobilized antibody, producing a color-developing and precipitating enzyme reaction product by allowing to react a coloring reagent with the labeling enzyme on the antibody immobilized layer to precipitate the enzyme reaction product on the antibody immobilized layer, allowing to totally reflect a light impinged on the sensor chip from the outside at an interface between the optical waveguide layer and the antibody immobilized layer, and observing to a physical value of the totally reflected light.

Abstract: The method for measuring the concentration of the measuring object uses a sensor chip comprising an optical waveguide layer and an antibody immobilized layer formed on the surface of the optical waveguide layer, which comprises immobilizing the measuring object and an enzyme-labeled antibody labeled with a labeling enzyme on the antibody immobilized layer of the sensor chip having an immobilized antibody, producing a color-developing and precipitating enzyme reaction product by allowing to react a coloring reagent with the labeling enzyme on the antibody immobilized layer to precipitate the enzyme reaction product on the antibody immobilized layer, allowing to totally reflect a light impinged on the sensor chip from the outside at an interface between the optical waveguide layer and the antibody immobilized layer, and observing to a physical value of the totally reflected light.

Abstract: This invention provides a method wherein a protein sparingly soluble in water, or a protein in a hardly extractable state, is detected sharply and easily in subsequent immunoreaction while high efficiency of extraction from a sample is maintained. Disclosed is a highly sensitive and easy immunoassay characterized in that a water-sparingly-soluble protein in a sample, or a protein in a hardly extractable state, is extracted/solubilized with an aqueous solvent containing an ionic surfactant at relatively high concentration, and then the protein in the extract is detected directly by an antibody raised against the protein previously denatured with the ionic surfactant.