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: .gamma.-GTP activity can be determined easily by using a stabilized substrate solution comprising .gamma.-L-glutamyl-p-nitroanilide and a modified cyclodextrin, together with an acceptor solution containing an acceptor for glutamic acid and measuring p-nitroaniline generated.

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: 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: 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: 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.

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 whch 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: A reduced form coenzyme can be determined by acting a peroxidase on a reduced form coenzyme in the presence of metal ions to generate hydrogen peroxide and measuring the amount of hydrogen peroxide colorimetrically.

Abstract: Peroxidic substances in a sample, e.g. one or more peroxidic substances in fats and oils or in an organic material, lipoperoxides in a living sample, etc. can be determined, directly in a sample or after extracting the lipoperoxides from a living sample with a solvent, by contacting the peroxidic substances with an oxidizable color reagent in the presence of a metallic compound produced from a metal which is able to have two or more valences to produce color, and measuring degree of coloring colorimetrically.