摘要:
A method of detecting or measuring homocysteine in a sample which comprises: (a) the step of treating a D-amino acid in the sample with a D-amino acid converting enzyme to thereby convert the D-amino acid into a substance not acting as the substrate of D-amino acid oxidase or D-amino acid acetyltransferase; (b) the step of reducing homocysteine in the sample with a thiol compound; (c) the step of treating the thus reduced homocysteine with methyltransferase and a methyl donor to thereby newly form a D-amino acid; and (d) treating the thus formed D-amino acid with the D-amino acid oxidase or the D-amino acid acetyltransferase in the presence of an SH reagent to thereby derive it into hydrogen peroxide and then coloring the thus formed hydrogen peroxide with the use of an oxidative color developing agent.
摘要:
8-(anilino)-1-naphthalenesulfonate (ANS) analogs and methods for their use in analyte detection assays are provided. The subject ANS analogs are characterized by having at least one non-hydrogen substituent on their phenyl moiety and producing a reaction product with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) or an analog thereof, e.g. MBTHSB, that exhibits reduced drift. In certain preferred embodiments, the subject ANS analogs are described by formula (I) wherein: n is 1 to 5; and X is a substituent other than H. The subject ANS analogs find use in a variety of applications, particularly in analyte detection assays, such as glucose detection assays.
摘要:
A method for determining ascorbic acid by quantitatively determining ascorbic acid in a sample by using an ascorbate oxidase (hereinafter referred to as "ASOD") capable of catalyzing a reaction of ascorbic acid of reduced form with oxygen to produce ascorbic acid of oxidized form and hydrogen peroxide, characterized by simultaneously conducting a reaction of ascorbic acid of reduced form with oxygen to produce ascorbic acid of oxidized form and hydrogen peroxide and a reaction of the resultant hydrogen peroxide with a chromogen in the presence of a peroxidase to produce a dye in the same reaction system in an aqueous medium in the presence of ASOD and the formed dye quantitatively determining. A method for quantitatively determining total ascorbic acid by adding a reducing agent capable of reducing ascorbic acid of oxidized form to ascorbic acid of reduced form to the above aqueous medium to conduct an enzymatic reaction, whereby total ascorbic acid present in a low concentration can be quantitatively determined. Another method for quantitatively determining total ascorbic acid by reducing ascorbic acid of oxidized form in the sample with a reducing agent capable of reducing ascorbic acid of oxidized form to ascorbic acid of reduced form and conducting an enzymatic reaction in the presence of a compound capable of depriving the reducing agent of the reducing power. A reagent for quantitatively determining ascorbic acid and a kit for quantitatively determining ascorbic acid used for the above quantitative determination methods. The above methods can be applied also to the screening for a clinical test, can simultaneously determine a plurality of analytes, and are simple.
摘要:
The invention relates to a multilayer analytical element for quantitatively measuring a component of a sample in the presence of a reagent capable of interacting with the sample. The multilayer analytical element of the invention comprises a solid support and a hydrophilic layer thereon, the hydrophilic layer being made of gelatin, polyvinyl alcohol or a mixture thereof and containing a developing agent and a color-producing agent in a total amount of 5 to 30 weight %, the developing agent and color-producing agent being present in a weight ratio of 1:0.3 to 1:3.0. The developing agent is capable of undergoing oxidation caused by the reagent in the presence of an oxidizing agent, whereby the developing agent in oxidized form reacts with the color-producing agent to form a colored product. The multilayer analytical element according to the invention can be used in medicine and pharmacology as well as in criminal law. It can be utilized for measuring cholesterol, chloride ions and glucose, thereby enabling the diagnosis of hypercholesterolemia, cysticfibrosis and diabetes.
摘要:
Dispositif d'analyse (14) permettant de mesurer la concentration d'un analyte soluble, tel que le cholestérol associé à HDL, dans un échantillon fluide contenant des composés d'interférence tels que le cholestérol associé à LDL ou le cholestérol associé à VLDL, qui peuvent être précipités sélectivement. Le dispositif comprend une matrice de criblage (26) pouvant séparer le matériau soluble et précipité passant au travers de la matrice, et un réservoir (34) qui contient un agent de précipitation lequel est efficace, dans une plage de concentration donnée, pour précipiter sélectivement les composés d'interférence. Le réservoir est conçu pour retarder la libération de l'agent, lors du contact avec l'échantillon fluide, pour maintenir la concentration de l'agent de précipitation en contact avec l'échantillon fluide dans la plage de concentration donnée. Le dispositif comporte en outre un tampon d'analyse (64, 66, 68, 70) par lequel l'analyte soluble présent dans l'échantillon fluide peut être analysé. Un procédé de séparation de lipoprotéines très denses (HDL) de lipoprotéines de faible et de très faible densités (LDL et VLDL) utilise une matrice en fibres de verre revêtues qui inhibe la liaison de HDL comme un échantillon fluide de sang contenant HDL et LDL et VLDL précipités passent au travers de la matrice.