Abstract: A liquid reagent in which a methylene blue compound color former is stably stored in a liquid state; and a method of stabilizing a methylene blue compound color former in a liquid state. A methylene blue compound color former is stabilized by causing it to coexist with either a quaternary ammonium compound having a C12 or higher hydrocarbon chain or a salt thereof in a liquid medium. Examples of the methylene blue compound color former include 10-(carboxymethylaminocarbonyl)-3,7-bis(dimethylamino) phenothiazine.

Abstract: The present invention provides a method for cleaving a glycated protein to obtain an amino acid or a peptide efficiently with a protease. By treating the glycated protein with the protease in the presence of a compound represented by R—X, the amino acid or the peptide is obtained by the cleavage. The R represents an alkyl compound with a carbon number of 9 or more, and preferably is straight-chain alkyl or straight-chain acyl with a carbon number of 9 to 16, branched-chain alkyl or branched-chain acyl with a carbon number of 10 to 40 and a main-chain carbon number of 9 to 16, or straight-chain alkyl that is substituted by cycloalkyl (a carbon number of the cycloalkyl ranges from 3 to 8, and a carbon number of the straight chain ranges from 4 to 13), where X is a sugar residue. Moreover, the glycated protein is, for example, glycated hemoglobin, and preferably ?-chain N-terminal amino acid or a ?-chain N-terminal peptide is cleaved by the protease treatment.

Abstract: A process for analyzing a sample by a capillary electrophoresis method is provided that allows the apparatus to be reduced in size, allows a high analytical precision to be obtained, and can be carried out easily. The analytical process of the present invention is a process for analyzing a sample by a capillary electrophoresis method. The analytical process includes preparing a capillary tube to be used for the capillary electrophoresis method, and performing electrophoretic separation of a complex of a sample and an anionic group-containing compound that are bonded together, in the capillary tube, wherein the capillary tube includes an anionic layer that is formed of the anionic group-containing compound and that is coated on the inner wall of the capillary tube, and the anionic layer is fixed to the inner wall of the capillary tube by a covalent bond.

Abstract: A new method of diagnosing postprandial hyperglycemia by indirectly measuring a blood glucose level is provided. Postprandial hyperglycemia is detected by measuring a glycation degree of lysine in hemoglobin, in which a side chain amino group of lysine is glycated (GHbLys %). Measurement of GHbLys % can be performed by cleaving hemoglobin by protease, treating a glycated part of a lysine residue in the obtained cleavage product of hemoglobin with fructosyl amino acid oxidase, and measuring a redox reaction between the glycated part and fructosyl amino acid oxidase.

Abstract: Each of the rising edges of PWM outputs is arranged for radiation noise reduction, by the assignment of suffix of output priority, by setting the rising edge of the first output at a start time of a cycle time, by evaluating an output margin at the falling edge of the first output relative to a current of the second output, by setting the rising edge of the second output in sync with the falling edge of the first output if the output margin is smaller than the current size of the second output. The same arrangement is used for subsequent outputs to totally reduce the current size in a simplified manner, thereby preventing the power loss and heat dissipation.

Abstract: A process for analyzing a sample by a capillary electrophoresis method is provided that allows the apparatus to be reduced in size, allows a high analytical precision to be obtained, and can be carried out easily. The analytical process of the present invention is a process for analyzing a sample by a capillary electrophoresis method. The process includes a step of preparing a capillary channel to be used for the capillary electrophoresis method and a step of electrophoresing a complex of a sample and an anionic group-containing compound that are bonded together, in the capillary channel, wherein the capillary channel includes an A layer that is coated on an inner wall thereof and a B layer that is coated on the A layer.

Abstract: A method of measuring HbA1c is provided that, even with a whole blood sample after storage, measurement accuracy substantially equal to a whole blood sample right after collection can be maintained. Whole blood is stored in a presence of a glycolytic inhibitor and protease is added to the stored whole blood sample to cleave hemoglobin in the whole blood sample. Then a glycated part of a hemoglobin fragment thereby obtained is treated with fructosyl amine oxidase. Thereafter, a glycation degree of HbA1c is determined by measuring a redox reaction between the glycated part and the fructosyl amine oxidase. Further, instead of storage of the whole blood in a presence of the glycolytic inhibitor, a strong electrolyte substance such as KCl, K2SO4, KNO, NaCl, Na2SO4, NaNO, MgCl2, MgSO4, Mg(NO)2, etc. is added to the whole blood after storage and a protease treatment is performed in a presence of the strong electrolyte substance.

Abstract: The present invention is directed to the described capillary electrophoresis apparatus and methods of using such apparatus for separating and analyzing components of a sample.

Abstract: An electrophoresis chip that can be small and simple and that can analyze a sample with high accuracy is provided. The electrophoresis chip includes an upper substrate 4, a lower substrate 1, an introduction reservoir 2a, a recovery reservoir 2b and a capillary channel for sample analysis 3x. The introduction reservoir 2a and the recovery reservoir 2b are formed in the lower substrate 1. The introduction reservoir 2a and the recovery reservoir 2b are in communication with each other via the capillary channel for sample analysis 3x. The introduction reservoir 2a receives a sample to be measured. The sample is electrophoretically introduced directly into the capillary channel for sample analysis 3x by creating a potential difference between the introduction reservoir 2a and the recovery reservoir 2b, and is also analyzed in the capillary channel for sample analysis 3x during the separation of the sample while the sample is being continuously supplied.

Abstract: The present invention provides a phenothiazine-derivative color-measuring method that can detect a phenothiazine-derivative color even at a wavelength longer than the wavelength that exhibits maximum absorption.

Abstract: The present invention provides a method for analyzing hemoglobin by capillary electrophoresis, that allows the apparatus to be smaller in size, allows a highly precise analysis to be obtained, and allows the analysis to be performed in a short period of time.

Abstract: An electrophoresis chip that enables an apparatus to be small, analysis time to be short and glycosylated hemoglobin to be analyzed highly accurately is provided. The electrophoresis chip includes an upper substrate 4, a lower substrate 1, a first introduction reservoir 2a, a first recovery reservoir 2b and a capillary channel for sample analysis 3x; the first introduction reservoir 2a and the first recovery reservoir 2b are formed in the lower substrate 1; and the first introduction reservoir 2a and the first recovery reservoir 2b are in communication with each other via the capillary channel for sample analysis 3x.

Abstract: A method for storing a tetrazolium compound stably is provided. The tetrazolium compound is stored in the presence of sodium azide. The tetrazolium compound (A) and the sodium azide (B) are present at a ratio (A:B) in the range from 1:0.02 to 1:6.2. Furthermore, when the tetrazolium compound is stored as a solution, the concentration of the sodium azide is in the range from 0.08 to 3.2 mmol/L and the concentration of the tetrazolium compound is in the range from 0.5 to 8 mmol/L. As the tetrazolium compound, it is preferable to use 2-(4-iodophenyl)-3-(2,4-dinitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium salt.

Abstract: An albumin denaturing agent for digesting an albumin by a protease efficiently is provided. The albumin denaturing agent contains quaternary ammonium having a hydrocarbon group with a carbon number of 12 or more, or a salt of the quaternary ammonium. The albumin in a sample is digested by the protease in the presence of the albumin denaturing agent, a glycated part of the thus obtained albumin digestion product and a FAOD effect a reaction, and a redox reaction between the glycated part and the FAOD is measured, thereby determining a ratio (GA (%)) of the glycated albumin of the glycated albumin with respect to the albumin.

Abstract: The present invention provides a method for cleaving a glycated protein to obtain an amino acid or a peptide efficiently with a protease. By treating the glycated protein with the protease in the presence of a compound represented by R—X, the amino acid or the peptide is obtained by the cleavage. The R represents an alkyl compound with a carbon number of 9 or more, and preferably is straight-chain alkyl or straight-chain acyl with a carbon number of 9 to 16, branched-chain alkyl or branched-chain acyl with a carbon number of 10 to 40 and a main-chain carbon number of 9 to 16, or straight-chain alkyl that is substituted by cycloalkyl (a carbon number of the cycloalkyl ranges from 3 to 8, and a carbon number of the straight chain ranges from 4 to 13), where X is a sugar residue. Moreover, the glycated protein is, for example, glycated hemoglobin, and preferably ?-chain N-terminal amino acid or a ?-chain N-terminal peptide is cleaved by the protease treatment.

Abstract: A liquid reagent in which a methylene blue compound color former is stably stored in a liquid state; and a method of stabilizing a methylene blue compound color former in a liquid state. A methylene blue compound color former is stabilized by causing it to coexist with either a quaternary ammonium compound having a C12 or higher hydrocarbon chain or a salt thereof in a liquid medium. Examples of the methylene blue compound color former include 10-(carboxymethylaminocarbonyl)-3,7-bis(dimethylamino) phenothiazine.

Abstract: The present invention provides a method of pretreating a sample containing a glycated amine as an analyte, thereby enabling highly reliable measurement of a glycated amine. A glycated amino acid in the sample is degraded by causing a fructosyl amino acid oxidase (FAOD) to act thereon, and thereafter, a FAOD further is caused to act on the glycated amine as the analyte in the sample to cause a redox reaction. The amount of the glycated amine is determined by measuring the redox reaction. The substrate specificity of the FAOD caused to act on the glycated amino acid may be either the same as or different from that of the FAOD caused to act on the glycated amine. When using the same FAOD, a FAOD is caused to act on the glycated amino acid to degrade it, and thereafter, the sample is treated with a protease to inactivate the FAOD and also to degrade the glycated amine.

Abstract: The present invention provides a method of preventing erroneous color development of N-(carboxymethylaminocarbonyl)-4,4?-bis(dimethylamino)diphenylamine sodium salt as a color-developing substrate, thereby improving the accuracy of measurement utilizing a redox reaction performed using the color-developing substrate. A tetrazolium compound, sodium azide, and the color-developing substrate are added to a sample in the presence of a surfactant. A reaction between an oxidizing substance derived from an analyte in the sample and the color-developing substrate, which develops color by oxidation, is caused by an oxidoreductase. By measuring the color developed, the amount of the oxidizing substance is determined. The concentrations of the respective components in the reaction solution are set so that 0.01 to 1 mmol of the tetrazolium compound, 0.003 to 0.5 mmol of the sodium azide, and 0.006 to 0.

Abstract: The present invention provides a fructosylamine oxidase which is obtainable by culturing Fusarium proliferatum, and purifying two types of fructosylamine oxidase (FAO) with different substrate specificities from the culture, and which is useful in the measurement of amadori compounds.

Abstract: The present invention provides a highly reliable method of measuring an analyte in a sample using a redox reaction. In this method, a formazan compound is added to a sample prior to a redox reaction so as to eliminate the influence of any reducing substance in the sample. Thereafter, a reducing substance or an oxidizing substance derived from the analyte is formed, and the amount of the formed substance is measured by the redox reaction. The amount of the analyte is determined from the amount of the formed substance thus measured. As the formazan compound, for example, 1-(4-iodophenyl)-3-(2,4-disulfophenyl)-5-(2,4-dinitrophenyl) formazan can be used.