78 results about "Sarcosine oxidase" patented technology

The invention provides methods for preparing a stable, multiple-use three enzyme biosensor for the amperometric determination of creatinine in biological liquids that has a useful lifetime that extends significantly beyond that of presently available amperometric biosensors. The biosensor prepared by the methods of the invention encompasses a plurality of immobilized enzymes that are applied to the biosensor as an enzyme-polymer composition. The enzymes, which can include creatinine amidohydrolase, creatine amidinohydrolase and sarcosine oxidase, are immobilized into the enzyme-polymer composition simultaneously as well as applied to the biosensor simultaneously. Prior to being immobilized, the enzymes can be chemically modified by attaching one or more polyethylene glycol (PEG) chains per enzyme monomer. The polymer component can be provided by a polyurethane membrane. The invention also provides a method of preparing a biosensor that limits the diffusion of silver ions emanating the reference electrode, thereby preventing, contact between the silver ions and the enzymes. Related methods of preparing an enzyme-polymer composition for incorporation into a multiple use three enzyme biosensor for the amperometric determination of creatinine in biological liquids also are provided. The invention also provides multiple-use biosensors and enzyme-polymer compositions prepared by the methods disclosed.

The invention discloses a detection kit for determining the content of creatinine in serum by an enzymic method. The detection kit comprises a reagent R1 and a reagent R2, wherein the reagent R1 contains 3-10g/L of buffering solution with the pH value being 7.5-8.0, 0.2-0.5g/L of EDTA, 0.5-2g/L of N-ethyl-N-(2-hydroxyl-3-sulfopropyl) m-toluidine sodium salt, 1 per mill-5 per mill of a surface active agent, 0.2-1g/L of sarcosine oxidase, 1-5KU/L of ascorbate oxidase, 2-5KU/L of creatinase and 0.5-1g/L of a stabilizing agent; the reagent R2 contains 3-10g/L of buffering solution with the pH value being 7.5-8.0, 0.1-0.5g/L of 4-aminoantipyrine, 0.1-0.4g/L of potassium ferricyanide, 2-8g/L of creatininase amidohydrolase, 1-6KU/L of peroxidase and 0.5-2g/L of a preservative. The detection kit disclosed by the invention is excellent in stability, strong in interference resistance and high in clinical application value.

A dry test strip for measuring creatinine (1) comprises: a support (2),a reagent layer (4) that is disposed on the support (2),a reagent holding layer (5) that is disposed on the reagent layer (4),and a connection layer (6) that is composed of an adhesive which adhesively bonds the reagent layer (4) to the reagent holding layer (5) and is formed in spot form, wherein the reagent layer (4) contains creatininase and 4-aminoantipyrine,the reagent holding layer (5) contains creatinase, sarcosine oxidase, peroxidase, and N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline,and the connection layer (6) delays arrival of a liquid sample spot-deposited on the reagent holding layer (5) at the reagent layer (4).

The invention relates to a composition for eliminating the interference of a calcium dobesilate medicine on creatininase-method detection. The composition comprises an R1 reagent, an R2 reagent and ahigh molecular oxidant, wherein the high molecular oxidant is one or more of high molecular peroxy acid, high molecular selenium oxide, high molecular sulfur chloride ether, N-substituted imide, water-soluble tetrazole and a Dess-Martin oxidant. The high molecular oxidant in the composition disclosed by the invention can react with the calcium dobesilate in a sample to be detected, the calcium dobesilate loses the effect of interfering enzyme-method creatinine detection and the accuracy of sarcosine-oxidase-method detection is improved, so that the problem of serious negative interference, caused by high-concentration calcium dobesilate in blood of a patient, on an enzyme-method creatinine project detection result when the patient orally takes the calcium dobesilate medicine is solved.

The invention is about a method of measuring the content of creatinine, and it also concerns the reagent box of creatinine diagnosis. This invention belongs to the field of medical testing and measuring technology. The reagent box is consisted of buffer solution, creatinine enzyme, creatine enzyme, sarcosine onidase, anaerooxidase and stabilizer. Firstly, we cause an enzyme-coupled reaction through mixing the sample and the reagent according to a certain proportion of volume; secondly, put the final reactant under the biochemical analyzer and test the absorbance variational situation (speed) of dominant wavelength; then we can get the content of creatinine. By using this invention, we can get the necessary measuring result with high sensitiveness and fine precision through biochemical analyzer, and the result would not be contaminated by material of internal and exogenous sources. Thus, this method can be conveniently promoted and applied.

The present invention discloses a protein, which still has sarcosine oxidase activity after being modified by adding, deleting, inserting or replacing at least one amino acid in the amino acid sequence constituting the protein having sarcosine ammoniaase activity, characterized by Improved stability in liquid compared to unmodified protein and/or reduced effect on L-proline compared to unmodified protein. Sarcosine oxidase has at least one of the following characteristics, namely, based on the effect of creatine on L-proline, measured at 37°C and pH 8.0, is 0.7% or less and the Km of L-proline The value is 150 mM or more; the method for producing sarcosine oxidase having excellent substrate specificity comprises culturing a microorganism capable of producing sarcosine oxidase and collecting sarcosine oxidase from the culture medium; and containing sarcosine A reagent for the detection of creatinine for amino acid oxidase.

The invention discloses a sarcosine oxidase affinity medium and a method for synthesizing and purifying sarcosine oxidase, which belong to the technical field of biologic engineering. The sarcosine oxidase affinity medium disclosed by the invention is prepared by connecting a sarcosine oxidase affinity ligand with a chromatography medium; preferably, the sarcosine oxidase affinity ligand is a substrate analog 4-amino pyrrole-2-carboxylic acid, and the chromatography medium is Sepharose or poly-chitosan; the invention further provides a synthesis method of the sarcosine oxidase affinity medium, and a method for purifying the sarcosine oxidase in a large scale by using the sarcosine oxidase affinity medium. By utilizing the sarcosine oxidase affinity medium disclosed by the invention, the sarcosine oxidase can be rapidly separated and purified in a large scale, and a sarcosine oxidase pure product can be obtained under the condition of one step affinity chromatography; and the whole purification step is short in time, the protein and activity recovering rate is high, and thus being applicable to large-scale popularization and application.

The invention belongs to the technical field of clinical in vitro diagnostic reagents and relates to a dry chemical reagent tablet for quantitatively measuring the concentration of creatinine and a preparation method of the dry chemical reagent tablet. The dry chemical reagent tablet comprises four laminations which are respectively a support layer, a color developing layer, a reagent layer and adiffusion layer distributed sequentially; and reagents in the reagent layer include a buffer system, a hydrophilic colloid, a creatine amidinohydrolase, sarcosine oxidase, peroxidase, a protective agent, a chelating agent, an activator and a surfactant; and reagents in the color developing layer include a chromogen, a creatine amidohydrolase, a hydrophilic colloid, and a surfactant. The dry chemical reagent tablet and the preparation method thereof of the invention have the advantages of simple operation process, high stability, high good repeatability and high accuracy of detection results, quantitative detection, wide linear range, simple and convenient preparation process, easiness in operation, low risk and low pollution. According to the dry chemical reagent tablet and the preparationmethod of the dry chemical reagent tablet of the invention, the reagents do not need to be prepared, and samples can be directly added dropwise; and the reagent tablet is dry and is free of moisture;the diffusion layer has a filtering function, so that hemolysis, bilirubin and ascorbic acid samples exert no significant interference on measurement results.

The invention relates to a creatinine assay kit and application thereof, and belongs to the technical field of biological detection. The creatinine assay kit is composed of a reagent R1 and a reagentR2; the reagent R1 is prepared from creatinase, catalase, sarcosine oxidase, 4-amino-antipyrine, an inhibitor and a buffer solution; and the reagent R2 is prepared from creatinase, catalase, a color developing agent, ascorbic acid oxidase, an inhibitor and a buffer solution. According to the creatinine assay kit, assaying is conducted through a sarcosine oxidase method, and the creatinine assay kit has the advantages of wide linear range, good stability and the like.

The invention relates to a sarcosine detection method based on a metal organic framework material. The sarcosine detection method is characterized in that sarcosine oxidase and catalase are wrapped bymeans of the metal organic framework material, so that the pair of cascade enzymes is limited in a smaller space, and the content of sarcosine is determined by adopting a chemiluminescence method after a cascade reaction. The sarcosine detection method adopts ZIF-8 to coat SOX and HRP; ZIF-8 has a large specific surface area and porous channels, so that a reaction substrate in a solution can penetrate through the channels to react with SOX and HRP, enrichment of the substrate around the enzymes is facilitated, and the local substrate concentration is increased; meanwhile, due to wrapping of ZIF-8, SOX and HRP are limited within the range of hundreds of nanometers, the distance between SOX and HRP is regulated and controlled, hydrogen peroxide generated by catalyzing sarcosine by means ofSOX can be effectively transmitted to HRP for a chromogenic reaction, and the reaction rate of the reaction cascade enzymes is increased.

The invention relates to a creatinine content detecting reagent and kit and manufacturing and using methods of the kit. The creatinine content detecting reagent comprises creatininase, creatinase, creatine oxidase and horseradish peroxidase; and a fluorescent dye, i.e., 5(6)-carboxyl-2,7-dichlordihydro fluorescein ester dipivalate comprises a dye bottom layer, a protease fixing layer and a top layer protecting layer. The using method has high selectivity; a protease has high specificity to reactants; the creatininase can be only used for catalyzing the hydrolysis reaction of creatinine, and does not have catalysis activity on other reaction substrates; three enzymes with high specificity are related to the detection process, so that the selectivity of the method is increased exponentially; the response fed by the kit is fluorescent response; and compared with certain methods for detecting color variations, the invention has the advantages of high sensitivity and interference resistance under the action of the inherent characteristics of fluorescent response.

The invention provides a creatinine detection kit and a use method thereof. The kit comprises a reagent R1 and a reagent R2, wherein the reagent R1 comprises creatinase, sarcosine oxidase, peroxidase,ascorbic acid oxidase, 2, 4, 6-tribromo-3-hydroxybenzoic acid and 3, 5-dichloro-2-hydroxybenzenesulfonic acid; and the reagent R2 comprises creatinase, peroxidase, potassium ferrocyanide and 4-aminoantipyrine. The creatinine detection kit provided by the invention can resist interference of etamsylate with the concentration of 300mg/L (the highest blood concentration) or below in a to-be-detectedsample, has a wider linear range (0-6000 millimoles/L), is applicable to detection of samples with high creatinine content and can correctly evaluate renal functions of surgical patients.

The invention relates to a creatinine kit capable of eliminating negative deviation interference in a creatinine determination caused by calcium dobesilate and etamsylate drugs in serum and a preparation method thereof. Key points of a technical scheme of the invention are that the creatinine kit includes a reagent R1 and a reagent R2, wherein the reagent R1 includes buffer, creatinase, sarcosineoxidase, ascorbic acid oxidase, peroxidase or catalase, serum albumin, nonionic surfactant, preservative, Trinder's reagent A, laccase or metalic acid salt; and the reagent R2 includes buffer, serum albumin, creatinine enzyme, preservative and Trinder's reagent B. The invention overcomes a defect of inaccurate creatinine determination due to the presence of the negative deviation caused by calciumdobesilate and etamsylat in serum samples when the clinical tests of creatinine determination are being carried out in various hospitals, and the invention is suitable for the detection of serum creatinine by an automatic biochemical analyzer.

The invention relates to the technical field of biology, and particularly relates to a reagent combination, a reagent or a kit for measuring creatinine content. The reagent combination comprises a reagent group 1 and a reagent group 2; the reagent group 1 comprises creatinase, sarcosine oxidase, ascorbic acid oxidase, chromogen and catalase; the reagent group 2 comprises creatinase, 4-aminoantipyrine and peroxidase; and the chromogen is selected from N-(2-hydroxy-3-sulfopropyl)-3, 5-dimethoxyaniline or sodium salt thereof and N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-5-dimethoxyaniline. An inhibitor is added into the measured reagent, so that generation of neocreatine and creatinine in the process of measuring is blocked, and interference existing in a sample in creatinine detection is lowered.