Abstract: A method of measuring an analyte, comprising a step of measuring a detectable substance by using a reaction system including a formation reaction of the detectable substance based on a chemical reaction of the analyte contained in a sample, wherein a layered inorganic compound is caused to exist in the reaction system including the formation reaction of the detectable substance, whereby high-sensitivity measurement is made possible, the detectable substance can be stabilized to improve accuracy of the measurement, a rate of a chemical reaction is increased to enable quick measurement, and high-sensitivity measurement is made possible even in a reaction system which forms an insoluble substance.

Abstract: A method of measuring an analyte, comprising a step of measuring a detectable substance by using a reaction system including a formation reaction of the detectable substance based on a chemical reaction of the analyte contained in a sample, wherein a layered inorganic compound is caused to exist in the reaction system including the formation reaction of the detectable substance, whereby high-sensitivity measurement is made possible, the detectable substance can be stabilized to improve accuracy of the measurement, a rate of a chemical reaction is increased to enable quick measurement, and high-sensitivity measurement is made possible even in a reaction system which forms an insoluble substance.

Abstract: A method of determining glycated hemoglobin is provided, by which a ratio of the glycated hemoglobin in a sample can be determined accurately and easily. The ratio of glycated hemoglobin can be determined by degrading a glycated hemoglobin in a whole blood sample selectively with a protease to give a glycated hemoglobin degradation product`; causing a redox reaction between a glycation site of the glycated hemoglobin degradation product and a fructosyl amino acid oxidoreductase; and determining this redox reaction. Further, as shown in FIG. 1, in a whole blood sample, there is a correlation between the ratio of the glycated hemoglobin determined by this method and an HbA1c concentration. Thus, without determining the glycated &agr;-amino group as a characteristic structure of HbA1c, an amount of HbA1c can be determined accurately and easily from the determined ratio of the glycated hemoglobin.

Abstract: A test strip having the capability of separating blood cells from whole blood, wherein it has a porous reagent layer comprising beads, an inorganic gel and a reagent that causes a detectable reaction with a substance to be detected, and a substrate that supports the reagent layer, wherein the beads are adhered to each other with the inorganic gel, and interstices are formed between the beads to trap a solid. The test strip can thus be used for separating blood cells from a whole blood including blood cells and plasma and detecting a substance to be detected, such as glucose, contained in plasma. The use of the test strip allows the measurement of a substance to be detected even by measurement of a transmitted light, the exhibition of good oxygen permeability, and thus can be used for measuring a substance to be detected with improved accuracy.

Abstract: A highly reliable method of measuring an analyte in a sample using a redox reaction. In this method, a tetrazolium compound is added to a sample prior to the redox reaction so as to eliminate the influence of any reducing substance in the sample, then a reducing substance or an oxidizing substance derived from the analyte is formed, the quantity of the formed substance derived from the analyte is measured by the redox reaction, and the quantity of the analyte is determined from the quantity of the formed substance derived from the analyte. As the tetrazolium compound, for example, 2-(4-iodophenyl)-3-(2,4-dinitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium salt can be used.

Abstract: A highly reliable method of measuring an analyte in a sample using a redox reaction. In this method, a tetrazolium compound is added to a sample prior to the redox reaction so as to eliminate the influence of any reducing substance in the sample, then a reducing substance or an oxidizing substance derived from the analyte is formed, the quantity of the formed substance derived from the analyte is measured by the redox reaction, and the quantity of the analyte is determined from the quantity of the formed substance derived from the analyte. As the tetrazolium compound, for example, 2-(4-iodophenyl)-3-(2,4-dinitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium salt can be used.

Abstract: A highly reliable method of measuring an analyte in a sample using a redox reaction. In this method, a tetrazolium compound is added to a sample prior to the redox reaction so as to eliminate the influence of any reducing substance in the sample, then a reducing substance or an oxidizing substance derived from the analyte is formed, the quantity of the formed substance derived from the analyte is measured by the redox reaction, and the quantity of the analyte is determined from the quantity of the formed substance derived from the analyte. As the tetrazolium compound, for example, 2-(4-iodophenyl)-3-(2,4-dinitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium salt can be used.

Abstract: The present invention provides a method for stabilizing trypsin, in which enzyme reaction of trypsin can be generated in a two-solution system, degradation of trypsin and its substrate can be prevented, and enzymatic activity of trypsin is improved compared to conventional methods, and which can be sufficiently applied to an automatic analyzer. An enzyme solution is prepared by dissolving trypsin in a buffer solution having a pH at which enzymatic activity of trypsin is active and containing calcium and/or manganese ions. It is preferable that the total concentration of the calcium ions and the manganese ions in the buffer solution is in the range of 3 to 10 mmol/l. It is also preferable that the concentration of the buffer solution is at least 10 mmol/l, and that the pKa of the buffer solution is higher than the pH of the buffer solution.

Abstract: A method for measuring the amount of glycosylated protein comprising the steps of decomposing glycosylated proteins with protease, causing a redox reaction between the decomposed products and an Amadori compound oxidoreductase, and determining the redox reaction so as to measure the amount of glycosylated proteins, wherein the decomposition with the protease is carried out in the presence of at least one substrate selected from the group consisting of metalloporphyrin, cytochrome and diaphorase.

Abstract: An integral multi-layer analytical element for analyzing bile acid sulfate comprising a support member, a reagent layer on said support member and a porous developing layer on said reagent layer, at least one of the reagent layer and developing layer containing bile acid sulfate sulfatase, 3.beta.-hydroxysteroid dehydrogenase and a combination of thio-NAD.sup.+ and reduced NAD or reduced NADP, in which the reagent layer contains a water-soluble polymer, a buffer and at least one component selected from the group consisting of sugar alcohols and Mn.sup.2+, which element suppresses the increase of blank values and prevents agglomeration of the enzyme during the preparation of a solution for forming the reagent layer.