Abstract: A method of a pretreatment of a sample for quantitating cholesterol characterized by, before measuring cholesterol contained in specific lipoproteins, treating the sample containing lipoproteins with an enzyme, the substrate of which is free cholesterol, optionally together with a reaction accelerator; a method for quantitating cholesterol in specific lipoproteins by using the above method; and a kit for quantitating cholesterol in specific lipoproteins to be used in the above quantification method. By using this quantification method, cholesterol in a specific fraction can be conveniently, accurately and efficiently quantitated fundamentally without resort to polyanion, etc. Thus, this method is appropriately usable in various automatic analyzers.

Abstract: The present invention provides a convenient, efficient method for assaying glycated protein, fructosyl peptide, or fructosyl amino acid which can be performed with reduced effect of fructosyl lysine compounds. The invention also provides a reagent for the assay. The invention is directed to a method for reducing the effect of a fructosyl lysine compound in an assay of fructosyl peptide or fructosyl amino acid contained in a sample, characterized by including causing an enzyme for assaying fructosyl peptide or fructosyl amino acid to act specifically on fructosyl peptide or fructosyl amino acid at a pH of 4.0 to 7.0 and measuring the product at a pH of 4.0 to 7.0; and a method for assaying glycated protein through the above method.

Abstract: A method of a pretreatment of a sample for quantitating cholesterol characterized by, before measuring cholesterol contained in specific lipoproteins, treating the sample containing lipoproteins with an enzyme, the substrate of which is free cholesterol, optionally together with a reaction accelerator; a method for quantitating cholesterol in specific lipoproteins by using the above method; and a kit for quantitating cholesterol in specific lipoproteins to be used in the above quantification method. By using this quantification method, cholesterol in a specific fraction can be conveniently, accurately and efficiently quantitated fundamentally without resort to polyanion, etc. Thus, this method is appropriately usable in various automatic analyzers.

Abstract: A method of storing/stabilizing an oxidizable color-assuming reagent, especially a leuco dye; and a stabilized reagent obtained thereby. The method of stabilizing an oxidizable color-assuming reagent comprises storing the oxidizable color-assuming reagent in a solution having a pH of 1 to 5.

Abstract: The present invention provides a convenient, efficient method for assaying glycated protein, fructosyl peptide, or fructosyl amino acid which can be performed with reduced effect of fructosyl lysine compounds. The invention also provides a reagent for the assay. The invention is directed to a method for reducing the effect of a fructosyl lysine compound in an assay of fructosyl peptide or fructosyl amino acid contained in a sample, characterized by including causing an enzyme for assaying fructosyl peptide or fructosyl amino acid to act specifically on fructosyl peptide or fructosyl amino acid at a pH of 4.0 to 7.0 and measuring the product at a pH of 4.0 to 7.0; and a method for assaying glycated protein through the above method.

Abstract: A method of a pretreatment of a sample for quantitating cholesterol characterized by, before measuring cholesterol contained in specific lipoproteins, treating the sample containing lipoproteins with an enzyme, the substrate of which is free cholesterol, optionally together with a reaction accelerator; a method for quantitating cholesterol in specific lipoproteins by using the above method; and a kit for quantitating cholesterol in specific lipoproteins to be used in the above quantification method. By using this quantification method, cholesterol in a specific fraction can be conveniently, accurately and efficiently quantitated fundamentally without resort to polyanion, etc. Thus, this method is appropriately usable in various automatic analyzers.

Abstract: A method for measuring a glycated protein, a glycated peptide, or a glycated amino acid is provided. In this method, proteolytic activity of the protease is controlled to thereby realize high accuracy of the measurement. Also provided is a reagent used in such a measurement. More specifically, this invention provides a method of measuring a glycated protein, a glycated peptide, or a glycated amino acid comprising the steps of treating a sample containing the glycated protein with a protease for releasing a glycated peptide or a glycated amino acid; reacting the released glycated peptide or glycated amino acid with corresponding oxidase for generation of hydrogen peroxide; and measuring the resulting hydrogen peroxide with peroxidase and an oxidizable color developing reagent; wherein reaction solution before the reaction with the oxidase is adjusted to a pH of 1 to 5; and a reagent used in such measurement.

Abstract: The present invention provides a convenient, efficient method for determining a substrate contained in a hemoglobin-containing sample and a reagent therefor, which can be employed for a variety of automatic analyzers while reducing interference of hemoglobin contained in the sample. A method for determining a substrate contained in a hemoglobin-containing sample through reaction of an oxidase with the substrate and optical measurement of the produced hydrogen peroxide by use of a peroxidase and an oxidizable color producing reagent, characterized in that the hemoglobin-containing sample is treated with an anionic surfactant selected from among a polyoxyethylene alkyl ether sulfate salt, a polyoxyethylene alkylphenyl ether sulfate salt, a polyoxyethylene alkyl ether phosphate, a polyoxyethylene alkyl sulfosuccinate, a polyoxyethylene alkyl ether carboxylate salt, a polyoxyethylene alkyl ether sulfonate salt, triethanolamine lauryl sulfate, an alkyl sulfosuccinate, and an alkylphenyl ether sulfonate salt.

Abstract: Provided is a method for stabilizing a leuco dye, the method including storing a leuco dye in a solution in the co-presence of a protease protein.

Abstract: A method of a pretreatment of a sample for quantitating cholesterol characterized by, before measuring cholesterol contained in specific lipoproteins, treating the sample containing lipoproteins with an enzyme, the substrate of which is free cholesterol, optionally together with a reaction accelerator; a method for quantitating cholesterol in specific lipoproteins by using the above method; and a kit for quantitating cholesterol in specific lipoproteins to be used in the above quantification method. By using this quantification method, cholesterol in a specific fraction can be conveniently, accurately and efficiently quantitated fundamentally without resort to polyanion, etc. Thus, this method is appropriately usable in various automatic analyzers.

Abstract: A method of a pretreatment of a sample for quantitating cholesterol characterized by, before measuring cholesterol contained in specific lipoproteins, treating the sample containing lipoproteins with an enzyme, the substrate of which is free cholesterol, optionally together with a reaction accelerator; a method for quantitating cholesterol in specific lipoproteins by using the above method; and a kit for quantitating cholesterol in specific lipoproteins to be used in the above quantification method. By using this quantification method, cholesterol in a specific fraction can be conveniently, accurately and efficiently quantitated fundamentally without resort to polyanion, etc. Thus, this method is appropriately usable in various automatic analyzers.

Abstract: A method of a pretreatment of a sample for quantitating cholesterol characterized by, before measuring cholesterol contained in specific lipoproteins, treating the sample containing lipoproteins with an enzyme, the substrate of which is free cholesterol, optionally together with a reaction accelerator; a method for quantitating cholesterol in specific lipoproteins by using the above method; and a kit for quantitating cholesterol in specific lipoproteins to be used in the above quantification method. By using this quantification method, cholesterol in a specific fraction can be conveniently, accurately and efficiently quantitated fundamentally without resort to polyanion, etc. Thus, this method is appropriately usable in various automatic analyzers.