133 results about "Cystatin C" patented technology

The invention provides an in-vitro detection method of human cystatin C. The method adopts a magnetic particle separation chemiluminescence immunoassay technology which is a product integrating an enzyme labeling technology, a magnetic particle separation technology and a chemiluminescence detection technology and has the advantages of high sensitivity, good specificity, good repetitiveness, and the like. The method can be used for measuring the content of cystatin C in the serum, the plasma and the urine of a person, and the indexes are mainly used for clinically evaluating the renal function and mainly used for monitoring the filtration rate of glomerulus, the renal tubular dysfunction and various secondary nephropathies.

A method for quantifying a neurodegenerative disorder in a patient that includes obtaining a fluid sample from the subject; measuring a protein biomarker complex in said fluid sample and correlating the measurement with mild cognitive impairment or Alzheimer's disease status. The biomarkers include those that comprise at least one of a transthyretin protein and/or a prostaglandin-H2 D-isomerase protein, and at least one second, different protein selected from a transthyretin, prostaglandin-H2 D-isomerase, beta-2-microglobulin, cystatin C, superoxide dismutase [Cu—Zn], plasma retinol-binding protein, phosphatidylethanolamine-binding protein, carbonic anhydrase 2, prostaglandin-H2 D-isomerase, and/or serotransferrin protein;

The invention provides a latex enhanced turbidimetric immunoassay kit for quantitatively detecting cystatin C. The kit comprises a reagent R1 and a reagent R2 which are independent from each other, wherein the reagent R1 is mainly prepared from a buffer solution 1, a stabilizing agent 1, a preservative 1, EDTA, accelerator and a protective agent 1; the reagent R2 is mainly prepared from polystyrene latex microspheres for crosslinking a cystatin C antibody, a buffer solution 2, a stabilizing 2, a preservative 2 and a protective agent 2, wherein the polystyrene latex microspheres and the cystatin C antibody are connected in a covalent cross-linking mode. The detection kit has the advantages of low preparation cost, good stability, good data repeatability and high detection sensitivity, is easy to store, and can be widely applied to clinical biochemical analyzers.

The invention provides a human cystatin C quantitative detection method. According to the method, a magnetic micro-particle separation technology and an enzymatic chemiluminescence technology are combined, the principle of a double-antibody sandwich one-step reaction method is adopted, and the method can be used for content determination of human cystatin C in serum, plasma and urine samples and assistance in diagnosis and treatment of various renal dysfunction diseases. The sensitivity of the method is not more than 0.01mu g/L, the quantitative detection range is 0.05-8mu g/L, the precision in analysis is less than 5%, the detection time is 10 minutes, the recovery rate of the added serum and urine is 90-115%, and the correlation analysis R2 with a reagent serum value detected by a latex-enhanced immunoturbidimetric method is 0.9862.

The invention provides a cystatin C detection kit and a preparation method thereof. The kit comprises a reagent R1, a reagent R2 and a cystatin C calibration product, wherein the reagent R1 comprisesa preservative, a surfactant, an emulsifier and a buffer solution; the reagent R2 comprises a cystatin C antibody, polystyrene latex microspheres, a latex microsphere activating agent, a sealing agent, an emulsifier, a preservative, a surfactant and a buffer solution. The cystatin C antibody is slowly dropwise added to an activated polystyrene latex microsphere solution, a polystyrene latex microsphere suspension coupled with the cystatin C antibody is obtained after a stirring reaction, sealing is performed, the antibody and latex microspheres are coupled together in a chemical crosslinking manner, and centrifugation, cleaning and ultrasonic resuspension processes in conventional methods are omitted. The production process is simplified, and the kit has the advantages of low blank absorbency, high sensitivity and precision and large linear range.

There is a demand for improved turbidimetric immunoassays for human Cystatin C in biological samples, especially in human clinical samples of body fluids. The present invention provides a turbidimetric immunoassay method and reagent set enabling measurement of human Cystatin C by turbidimetric methods, resulting in a surprisingly stronger and faster turbidimetric signal than in the present state of the art. The increased and faster signal is accomplished by the use of new reagents and compositions, and enables shorter assay times and kinetic reading with a stronger signal, improving overall assay speed and quality. Improved robustness to lipid interference and improved linearity is achieved.

The present invention relates to a method of predicting the risk of a subject developing a cardiovascular event, comprising determining the presence of a biomarker that is indicative of the risk of developing a cardiovascular event in exosomes from the subject. The exosomes are suitably isolated from a body fluid selected from serum, plasma, blood, urine, amniotic fluid, malignant ascites, bronchoalveolar lavage fluid, synovial fluid, breast milk, saliva, in particular serum. The biomarker is selected from the proteins Vitronectin, Serpin F2, CD14, Cystatin C, Plasminogen, Nidogen 2 or any combination of two or more of these proteins.

The invention relates to a cystatin C fluorescent microsphere immunochromatographic quantitative test strip, and a test card including the test strip. The test strip comprises a base plate, a sample pad, a binding pad, a nitrocellulose membrane and an absorbent paper, the binding pad is provided with a fluorescent microsphere-labeled cystatin C monoclonal antibody, and the nitrocellulose membraneis coated with a detection line formed by a cystatin C polyclonal antibody or a monoclonal antibody and a quality control line formed by a sheep anti-mouse IgG polyclonal antibody. The test strip realizes the rapid and quantitative detection and analysis of cystatin C, has the advantages of high sensitivity, good accuracy, wide linear range, short detection time and convenience in use, and can meet bedside emergency and onsite rapid detection demands.

The invention provides a cystatin C latex-particle-enhanced turbidimetry detection reagent kit and application thereof.The reagent kit comprises a reagent R1 and a reagent R2.The reagent R1 is prepared from a buffer solution, inorganic salt, a surfactant, a preservative, a stabilizer and interference elimination protein.The reagent R2 is prepared from a buffer solution, inorganic salt, a surfactant, a preservative, a stabilizer and a polystyrene latex particle mixture, and the polystyrene latex particle mixture is interlinked with a cystatin C antibody.The reagent kit based on latex-particle-enhanced turbidimetric immunoassay (PETIA) can be generally applied to analysis of various full-automatic biochemical analyzers and is short in assay time, good in specificity, high in precision and good in accuracy when used.

The invention relates to the field of medical immunology in vitro diagnosis, and especially provides a detection kit for detecting cystatin C in serum. The detection kit comprises a reagent R1, a reagent R2 and calibration materials. The ingredients of the reagent R1 are a Tris buffer with a concentration of 0.01-0.05mol/L, PEG 6000 with a concentration of 10-40g/L, NaN3 with a concentration of 0.5-1.5g/L, and sodium chloride with a concentration of12-20g/L, and the pH value is 8.0-8.5. The ingredients of the reagent R2 are a Tris buffer with a concentration of 0.01-0.02mol/L, and polystyrene latex granules coated by goat-anti-human cystatin C polyclonal antibodies with a concentration of 0.5-3.0 g/L. The calibration materials are six gradient standards with cystatin C and the contents of cystatin C are 0.1, 0.5, 1.0, 2.0, 4.0 and 8.0mg/L. The solution is a Tris buffer with a concentration of 0.01mol/L. The kit has simple composition, good stability and high accuracy.

The invention discloses a recombined human cystatin-C protein with natural activity and a preparation method thereof. According to the preparation method, lots of stable recombined human cystatin-C proteins are expressed and purified by employing a gene engineering technique, and the recombined human cystatin-C proteins are cut by utilizing the protease, so that the recombined human cystatin-C protein has high natural activity. The recombined human cystatin-C protein can be used for immune preparation of monoclonal antibodies and multi-antibody blood serum, and excellent raw materials are provided for preparing stable cystatin-C detection agents and quality control products thereof.

The invention relates to nanometer antibodies to human cystatin C and high-sensitivity quantitative-detection kits thereof. The invention reveals nanometer antibodies and monoclonal antibodies to different epitopes of cystatin C, and the antibodies have good compatibility with cystatin C. Through usage of the nanometer antibodies and the monoclonal antibodies, a series of kits capable of conveniently, rapidly and accurately detecting cystatin C can be prepared. The invention provides the nanometer antibodies which can be used for matched detection of cystatin C. With the kits provided by the invention, cystatin C antigens can be sensitively detected, and good repeatability and stable results are obtained; the kits can realize rapid detection and are convenient and fast to use, and the nanometer antibodies need low production cost and are easily available.

The invention discloses a combined application of a cystatin SN and an alpha-fetoprotein (AFP), and particularly discloses the application of the cystatin SN and the AFP in preparation of a marker for diagnosis and predicting of liver cancer. The invention also discloses a capture agent of the liver cancer marker. A liver cancer detection kit is formed by combining the capture agent with conventional reagents. The obtained kit has the advantages of good specificity, high sensitivity and the like, can be used for early diagnosis of liver cancer, therapeutic effect evaluation in a therapeutic process and monitoring of metastasis and recurrence after therapy, and has test results sooner than clinical symptoms.

The present invention provides a method for diagnosis or prognosis of IgA nephropathy in a subject based on detection of the expression level of one or more biomarker genes selected from the group consisting of thymosin β4 (Tmsb4), serine or cysteine proteinase inhibitor clade E member 2 (Serpine2), secreted phosphoprotein 1 (OPN), butyrophilin-like-2 (BTNL2), S100 calcium binding protein A8 (S100A8), Cystatin C (CysC), and any combination thereof.

The invention relates to a cystatin C detection kit and a preparation method thereof. The kit includes reagents R1 and R2 which are independent of each other. The reagent R1 mainly consists of a buffer solution 1, an inorganic salt ion 1, a stabilizer 1, Preservative 1, solubilizer 1 and accelerator 1; the reagent R2 is mainly composed of polystyrene microspheres of cross-linked cystatin C antibody, buffer 2, stabilizer 2, solubilizer 2, preservative 2 and protection Reagent 2, the polystyrene microspheres are connected to the cystatin C antibody through physical adsorption or chemical cross-linking, and are encapsulated by β-cyclodextrin. The cystatin C detection kit of the invention has the advantages of low preparation cost, good stability, easy storage, good data accuracy and high detection sensitivity, and can be widely used in clinical biochemical instruments.

The invention discloses a fluorescent probe for detection of cystatin C and a construction method thereof, relates to the molecular biological and microbiological technical fields, and is characterized in that the construction method comprises the steps: with Cys-C as a target, screening to obtain a Cys-C specific-binding recombinant phage by using a phage surface random displayed 12-mer peptide library, extracting single stranded DNA of the recombinant phage, carrying out sequencing and sequence comparison, to obtain a sequence Gln-Val-Asn-Gly-Leu-Gly-Glu-Arg-Ser-Gln-Gln-Met of a Cys-C specific affinity ligand having the molecular weight of 1346.5, then carrying out solid phase polypeptide synthesis and fluorescence labeling to obtain the fluorescent probe FITC-Acp-Gln-Val-Asn-Gly-Leu-Gly-Glu-Arg-Ser-Gln-Gln-Met having the molecular weight of 1848.7 and specifically bond with the Cys-C. The fluorescent probe and the construction method thereof have the beneficial effects: 1, a brand new 'tool' is provided for specific identification and content detection of the Cys-C; and 2, the fluorescent ligand peptide probe not only can qualitatively identify the Cys-C, but also can quantitatively detect the content of the Cys-C in samples.

The invention provides a cystatin C latex-enhanced turbidimetry detection kit. The cystatin C latex-enhanced turbidimetry detection kit comprises double liquid components, namely, a reagent R1and a reagent R2, wherein the reagent R1 is prepared from 10 to 100 mM/L buffer solution, 5 to 50g/L stabilizer and 0.1 to 1g/L preservative, wherein purified water is taken as the solvent; the reagent R2 isprepared from 10 to 100mM/L buffer solution, 0.1 to 1 percent surfactant, 5 to 50g/L stabilizer, 0.1 to 1g/L preservative, 1 to 10 percent latex microspheres crosslinking with a recombinant antihumanCys-C single-chain antibody, and 2 to 15 percent of latex microspheres crosslinking with a goat antihuman Cys-C polyclonal antibody, wherein purified water is taken as the solvent. The invention further provides preparation and application methods of the cystatin C latex-enhanced turbidimetry detection kit. By adopting the detection kit, the advantages of a polyclonal antibody detection kit and amonoclonal antibody detection kit are combined, and the specificity and sensitivity of detection can be enhanced simultaneously.

The invention provides a method for treating amyotrophic lateral sclerosis (ALS) in a subject. The method comprises administering to the nervous system of the subject a composition comprising a thyroxine protein or a therapeutic fragment or pharmacologic mimic thereof and a pharmaceutically acceptable carrier. The invention also provides a method for treating ALS in a subject that comprises administering to the subject a transthyretin protein, 7B2 protein, a cystatin C protein, a neuroendocrine protein, a cysteine protease inhibitor, or an inhibitor of an enzyme that processes a 7B2 protein. In addition, the invention provides methods for determining the susceptibility of a subject to developing ALS and for determining the progression of ALS in a subject.

The invention discloses a recombinant human cystatin C coding gene and an expression method. The nucleotide sequence of the coding gene is shown in SEQ ID NO:1, and the expression method of recombinant human cystatin C protein comprises the following steps that the recombinant human cystatin C coding gene is inserted into a polyclone locus of a prokaryotic expression carrier, a recombinant expression plasmid is constructed, the recombinant expression plasmid is converted to an expression host bacterium escherichia coli, and positive clone bacteria are screened out to obtain engineering bacteria; and the engineering bacteria are fermented, induced, separated and purified to obtain the recombinant human cystatin C protein. The recombinant human cystatin C coding gene provided by the invention can express the human cystatin C protein, the operation is convenient, the purity of the human cystatin C protein expressed by the coding gene reaches more than 90%, the expression efficiency is high, and no higher expression efficiency exists currently.

The invention relates to the technical field of in-vitro diagnostic reagents and particularly relates to a cystatin C detection reagent and method. The detection reagent is composed of a reagent 1 and a reagent 2. The reagent 1 comprises ammonium chloride, polyoxyethylene lauryl ether, sodium chloride, PEG 6000, a preservative and water. The reagent 2 comprises latex microspheres coated with a cystatin C monoclonal antibody, a Tris-HCl buffer solution, sucrose, gelatin, NP30, a preservative and water. The detection reagent has high detection result accuracy, a good precision, a wide linear range, good specificity, good stability and strong anti-interference ability, can be conveniently detected on a full-automatic biochemical analyzer, has a wide application range and is easy to promote.

The invention discloses a method for expressing and purifying recombinant human cystatin C proteins by using a eukaryon expression system. Because posttranslational modification and other mechanisms are lacked in a pronucleus expression system, the expressed and purified proteins have the defects of low activity and large structural difference as compared with the natural proteins, which results in that a cystatin C detection agent is difficult in the establishment process by using a monoclonal antibody prepared from Escherichia coli source recombinant cystatin C proteins. In the method, the defects of the pronucleus expression are overcome by utilizing the eukaryon expression system so as to obtain the high-activity recombinant human cystatin C protein, and a powerful basis is provided for obtaining a high-quality antibody.