33 results about "Creatinase" patented technology

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.

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 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 discloses a creatinase mutant with improved heat stability, belonging to the field of enzyme engineering. A nucleotide sequence for coding the creatinase mutant is as shown in SEQ ID No. 1, SEQ ID No. 2, SEQ ID No. 3, SEQ ID No. 4 or SEQ ID No. 5. Compared with the half-life period of wild type creatinase, the half-life period of the creatinase mutant is respectively increased by 6.9, 3.7, 3.4, 1.6 and 1.2 times, so that the creatinase mutant is more suitable for industrial application.

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.

The invention discloses a kit and method for measuring creatinine. The kit comprises a first reagent, and the first reagent is prepared from monopotassium phosphate, dipotassium phosphate, ethylenediamine tetraacetic acid, Brij 35, Tween 80, ascorbic acid oxidase, creatinase, sarcosine oxidase, TOOS, peroxidase, potassium ferrocyanide, gentamicin sulphate and Tween 30. The method comprises the following steps: (1) the first reagent and a second reagent are dissolved according to the raw material components and content; (2) the dissolved first reagent is added into a to-be-measured sample; (3)the dissolved second reagent is added; and (4) the absorptivity of a solution under the wavelength of 546 nm is measured. According to the kit and method for measuring the creatinine, the precision and accuracy are high, and stability is achieved.

The invention relates to the field of biochemical detection, in particular to a detection kit for measuring creatinine through an enzyme method and a using method thereof. The kit comprises various reagents of sarcosine oxidase, creatinase, catalase, a buffer solution and the like prepared by using a genetically engineered bacterium GLYH18 prepared by a LYH18 bacterial strain with the preservationnumber of CGMCC No.17306, the sample is mixed with the reagents, and then, the final reactant is placed under a biochemical analyzer to detect the change condition of absorbance so as to measure thecontent of creatinine. The preparation method of the sarcosine oxidase in the kit is simple and low in cost, the content of creatinine in the sample can be quickly and accurately measured by the kit with the enzyme added, the kit can be kept stable at room temperature, which facilitates practical application and better facilitates industrial production.

The invention discloses a method for improving the heat stability of creatinase, and belongs to the fields of genetic engineering and enzyme engineering. According to the method, a mutant is obtained by carrying out amino-acid substitution and mutation on the basis of the creatinase from a Pseudomonas putida source. By comparing the mutant H125C/L130C provided by the invention with wild-type creatinase, the Tm value is increased by 8.2 DEG C, and the heat stability is obviously improved. Through the method provided by the invention, the heat stability of the creatinase is effectively improved.

The invention relates to the technical field of serum creatinine determination, and in particular relates to a serum creatinine detection reagent ball and a serum creatinine detection chip. According to the serum creatinine detection reagent ball and the serum creatinine detection chip containing the serum creatinine detection reagent ball, interference of vitamin C in a detection sample can be eliminated through ascorbic acid oxidase, and interference of bilirubin can be eliminated by taking a bilirubin interference removing agent as an oxidizing agent; interference of endogenous creatine, sarcosine and peroxide existing in a detection sample is eliminated through creatinase, sarcosine oxidase and peroxidase respectively. The serum creatinine detection reagent ball and the serum creatinine detection chip provided by the invention have relatively strong anti-interference capability on original interferents in serum and drug interferents taken by patients, and the precision of a detection result is high.

The invention discloses a creatinine detection reagent capable of resisting interference of medicines such as calcium dobesilate. The creatinine detection reagent comprises a first reagent and a second reagent, wherein the first reagent comprises 3-(N-morpholinyl)propanesulfonic acid, TOOS, gentamicin, sarcosine oxidase, creatinase, ascorbic acid oxidase and catalase, and the second reagent comprises 3-(N-morpholinyl)propanesulfonic acid, 4-AAP, creatininase amidohydrolase, peroxidase, preservative and potassium ferrocyanide; the first reagent and/or the second reagent further comprise/comprises piperidine oxygen radicals. According to the creatinine detection reagent provided by the invention, the interference effect of medicines such as calcium dobesilate can be reduced, the accuracy ofcreatinine detection in clinical detection is ensured, and a creatinine detection method with a wide linear range, strong medicine interference resistance and high accuracy is realized.

The invention provides an electrode for detecting creatinine by an electrochemical method. The electrode comprises an electrode material base layer, the outer surface of the electrode material base layer is covered with an electron mediator enhancement layer; an enzyme composition capable of reacting with creatinine to generate hydrogen peroxide is fixed on the outer surface of the electron mediator enhancement layer; the electrode material base layer is composed of carbon paste or graphite containing Prussian blue; the enzyme composition is prepared from creatininase, creatinase and sarcosine oxidase according to the ratio of (3.75-6.25) to (1.25-2) to (0.75-1.25). The invention also provides test paper and a biosensor based on the electrode. The invention also provides a preparation method for preparing the electrode and the test paper, and a method for detecting the creatinine level by using the biosensor. The test paper provided by the invention can be used in various portable and rapid small electrochemical detection devices, and can realize rapid and convenient clinical detection or home monitoring of blood and urine creatinine.

The invention relates to a method for determining the activity of creatinine, and also the reagent kit for creatinine diagnosis. The reagent kit comprises cushioning solution, pyroracemic acid, phosphoenolpyruvate phosphatase, creatinine enzyme, creatinase, urease, phosphoenolpyruvate carboxylase, pyruvic oxidase, peroxydase, stabilizer, and deacidized chromogen combination. By mixing sample and reagent of a predetermiend volumetric ratio, generating coupling reaction between them, subjecting the final reactant to biochemiscal analyser, the main wavelength absorbancy variance ratio (speed) can be detected, and the creatinine content can thus be measured. The method of the invention can be used to obtain the needed measurement result purely through biochemical analytic instruments, and advantages of the method include higher sensibility, better accuracy, less susceptibility to contamination of internal or external materials, and easy application.

The invention discloses a method for improving pH stability of creatinase, and belongs to the field of enzyme engineering. According to the method, creatinase of which the pH stability is improved and the kcat/Km is only reduced by 24 percent is obtained by modifying free creatinase homodimer through polylysine. The method is mild in conditions and easy to operate, and is more suitable for industrial application; convenience is provided for the application of the creatinase to the fields, such as medical diagnosis. Moreover, the method provided by the invention also provides a feasible way for stability transformation of other multi-subunit enzymes.