Abstract: The present invention discloses a method of measuring iron concentration in a sample. The method includes bringing iron contained in the sample into contact with a metallochromic indicator for iron in the presence of lithium ion and determining the iron concentration based on the degree of resultant coloring. The present disclosure further includes a reagent and a kit using therefor.

Abstract: The present invention discloses a method of measuring iron concentration in a sample, characterized by bringing the iron contained in the sample into contact with a metallochromic indicator for iron in the presence of lithium ion and determining the iron concentration based on the degree of resultant coloring, a reagent and a kit using therefor.

Abstract: There is provided a method and kit for measuring the amount of an objective constituent contained in a specific lipoprotein in a biological sample such as serum and plasma, specifically for measuring the amount of cholesterol contained in high density lipoprotein, which can be applicable to clinical tests.

Abstract: There is provided a method and kit for measuring the amount of an objective constituent contained in a specific lipoprotein in a biological sample such as serum and plasma, specifically for measuring the amount of cholesterol contained in high density lipoprotein, which can be applicable to clinical tests.

Abstract: Disclosed is a hybrid enzyme containing a foreign peptide, the hybrid enzyme having an enzyme activity similar to that prior to the substitution or insertion of the peptide, and having a property that the hybrid enzyme activity is modulated or modified when a material having binding ability to the peptide introduced by substitution or insertion is bound to the peptide moiety. Using the hybrid enzyme, it becomes possible to assay a trace amount of CRP in a sample by a homogeneous colorimetry, and a macromolecule materials can be easily assayed in a homogeneous system.

Abstract: There is provided a method and kit for measuring the amount of an objective constituent contained in a specific lipoprotein in a biological sample such as serum and plasma, specifically for measuring the amount of cholesterol contained in high density lipoprotein, which can be applicable to clinical tests.

Abstract: The amount of cholesterol in low density lipoproteins in a sample can be measured by contacting the sample with one or more reagent solutions to carry out the reaction in the presence of a polyanion and an amphoteric surfactant, followed by optical measurement of the reaction product.

Abstract: The present invention is to provide a method for measuring an amount of cholesterol in low density lipoproteins (LDL-cholesterol) in a sample specifically at high accuracy and a reagent used in this method, and the present invention can attain such effect that direct measuring an amount of LDL-cholesterol by widely used automatic analyzers can be conducted by using the invention, which has not been possible after known methods.

Abstract: Cholesterol in low density lipoproteins can be measured specifically and precisely by optically measuring a reaction product of a living sample with cholesterol oxidase or cholesterol dehydrogenase in the presence of an amphoteric surfactant. In addition to the above processes for measurement, the present invention provides reagent compositions and kits for measuring cholesterol in low density lipoprotein.

Abstract: A stable two-part liquid reagent composition for measuring creatine kinase activity contains, in the first part, adenosine 5'-adiphosphate, kexokinase or glucokinse, nicotinamide adenine dinucleotide (phosphate), glucose-6-phosphate dehydrogenase, and thioglycerol, 2-mercaptoethanol, or 2-mercaptoethanesulfonic acid or a salt thereof; and contains, the second part, creatine phosphate at a pH of 7.5 to 10.0. Glucose and magnesium ions can be included in either part or in both parts. The two-part composition is stable even after being stored for 3 months at 10.degree. C.

Abstract: A substrate or an enzymatic activity in a body fluid can be measured accurately without influences of interfering substances such as bilirubin by reacting an oxidase corresponding to an analyte with the analyte or an oxidase corresponding to a substance produced by enzymatic reaction with the substance in a measuring system containing one or more cationic and/or amphoteric surfactants, followed by optical measurement of hydrogen peroxide produced by the reaction.

Abstract: A process for the determination of peroxidase activity or hydrogen peroxide in a clinical sample colorometrically by adding to the sample a reduced form coenzyme, a reagent selected from amines, phenols, and naphthols, a compound which is colored in the reduced form, and peroxidase or an aqueous solution of hydrogen peroxide. The process is essentially unaffected by the presence of ascorbic acid, bilirubin or other reducing substances of body fluids.

Abstract: A method for decomposing ascorbic acid in a sample is descirbed wherein in the method water and dehydroascorbic acid are produced without generation of hydrogen peroxide characterized in that the decomposition is conducted in the presence of copper ion, peroxidase and at least one other compound selected from the group consisting of:4-aminoantipyrine,3-methyl-2-benzothiazolinonehydrazone,2,2'-azinobis(3-ethylbenzothiazoline-6 sulphonic acid),a triphenyl methane type leuco compound,a phenol comound.an aniline compound, anda naphthol compound.

Abstract: An aqueous solution containing a tetrazolium compound used for determining superoxide ions can be stabilized by adding .beta.-cyclodextrin and/or a derivative thereof and/or .gamma.-cyclodextrin.

Abstract: Superoxide dismutase activity is determined by measuring hydrogen peroxide produced by using superoxide anion as a substrate and acting superoxide dismutase thereon in the presence of an electron carrier. When maleimide or a derivative thereof, and if necessary, a carbonyl compound, and if further necessary bromine ions and/or citric acid or a salt thereof are added to the electron carrier, the sensitivity and the linearity of calibration curves are further improved.

Abstract: Disclosed herein is a method of quantitatively measuring an oxidative substance with avoiding influences of a coloring-interfering substance in the quantitative measurement of the oxidative substance by using a triphenyl methane type leuco coloring matter as a coloring reagent. Disclosed herein is also such an oxidative quantitative measurement in which the coloring sensitivity can be further adjusted. In order to avoid the influences of the coloring-interfering substance, there is employed at least one kind of (i) uricase, (ii) an anionic surface active agent and (iii) a metal chelate compound. As the triphenyl methane type leuco coloring matter, use may be made of a compound of the general formula (I): ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be the same as or different from one another, represent a hydrogen atom or a lower alkyl group, and X.sub.1 and X.sub.2, which may be the same as or different from each other, represent a hydrogen atom, --SO.sub.3 M.sub.1, --COOM.sub.2, --O(CH.

Abstract: Cholesterol in a sample can be determined quantitatively by measuring colorimetrically superoxide ion generated by treating the sample with cholesterol oxidase. Similarly, a substrate such as glucose, etc., can be determined quantitatively by measuring the generated superoxide ion colorimetrically, said oxidase treatment and measuring of the generated superoxide ion being conducted by using a reagent composition comprising (a) an oxidase, (b') iron complex of porphyrin or ion chelate of complexane, (c) an amine and/or a phenol, (d) a thiol compound, (e) a color producing reagent to be reduced, and if necessary (f) a chelating agent.

Abstract: A substrate in a sample can be determined quantitatively by measuring colorimetrically superoxide ion generated by treating the sample with a specific oxidase corresponding to the substrate to be determined, said oxidase treatment and measuring of the generated superoxide ion being conducted by using a reagent composition comprising (a) an oxidase, (b) peroxidase, (c) a phenol and/or an amine, (d) a thiol compound, (e) a color producing reagent to be reduced, and if necessary (f) a chelating agent.

Abstract: Disclosed herein is a novel compound which is excellent in solubility to water around a neutral range, stable in an aqueous solution state for a long period of time, and high in coloring sensitivity with a stable coloring development, and is represented by the general formula (I): ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be the same as or different from one another, represent lower alkyl groups, and X.sub.1 and X.sub.2 both represent --O(CH.sub.2).sub.n SO.sub.3 M in which M is a hydrogen atom, an alkali metal ion or NH.sub.4.sup.+, and n is an integer of 2-4, or either of X.sub.1 and X.sub.2 represents --O(CH.sub.2).sub.n SO.sub.3 M in which M and n are the same meanings as given above and the other represents a hydrogen atom. This reagent is hardly susceptible of the influence of the serum components such as hemoglobin, bilirubin and so on due to its color having absorption on a longer wavelength side.

Abstract: In a process for measuring the activity of a dehydrogenase or the amount of substrate reacted in the presence of the dehydrogenase using NAD or NADP as coenzyme and a tetrazolium salt as a color-producing reagent, when at least one member selected from the group consisting of dodecyl sulfate, decyl sulfate, dodecylbenzenesulfonic acid, and salts thereof is used as a reaction stopper, resulting in enhancement of coloring, stability of the produced color and prevention of the produced formazan compound from staining the laboratoryware.