470 results about "Avidin" patented technology

Cyanine and related dyes, such as merocyanine, styryl and oxonol dyes, are strongly light-absorbing and highly luminescent. Cyanine and related dyes having functional groups make them reactive with amine, hydroxy and sulfhydryl groups are covalently attached to proteins, nucleic acids, carbohydrates, sugars, cells and combinations thereof, and other biological and nonbiological materials, to make these materials fluorescent so that they can be detected. The labeled materials can then be used in assays employing excitation light sources and luminescence detectors. For example, fluorescent cyanine and related dyes can be attached to amine, hydroxy or sulfhydryl groups of avidin and to antibodies and to lectins. Thereupon, avidin labeled with cyanine type dyes can be used to quantify biotinvlated materials and antibodies conjugated with cyanine-type dyes can be used to detect and measure antigens and haptens. In addition, cyanine-conjugated lectins can be used to detect specific carbohydrate groups. Also, cyanine-conjugated fragments of DNA or RNA can be used to identify the presence of complementary nucleotide sequences in DNA or RNA.

The invention relates to the field of analyzing immunological determination, in particular to a method for immunological detection by combining an acridinium ester labeling technology with general magnetic particles and an immunological determination (quantitative/qualitative) kit which is prepared by utilizing the method. According to the method disclosed by the invention, substances, such as acridinium ester or acridine sulfonamide are used for labeling and detecting an antigen or an antibody, biotin is used for labeling and capturing the antigen or the antibody, and the immunological determination of biomolecules is carried out by combining the general (chain enzyme) avidin labeled magnetic particles. The method disclosed by the invention has the advantages of high sensitivity, wide detection range and capabilities of realizing the automation easily and having a wide application prospect in the field of the immunological detection.

A fusion protein for delivery of a wide variety of agents to a cell via antibody-receptor-mediated endocytosis comprises a first segment and a second segment: the first segment comprising a variable region of an antibody that recognizes an antigen on the surface of a cell that after binding to the variable region of the antibody undergoes antibody-receptor-mediated endocytosis, and, optionally, further comprises at least one domain of a constant region of an antibody; and the second segment comprising a protein domain selected from the group consisting of avidin, an avidin mutein, a chemically modified avidin derivative, streptavidin, a streptavidin mutein, and a chemically modified streptavidin derivative. Typically, the antigen is a protein. Typically, the protein antigen on the surface of the cell is a receptor such as a transferrin receptor-or an insulin receptor. The invention also includes an antibody construct incorporating the fusion protein that is either a heavy chain or a light chain together with a complementary light chain or heavy chain to form an intact antibody molecule. The invention further includes targeting methods and screening methods.

The invention discloses a high-flux typed analyzing technique, material and agent box of nucleic acid based on stream-oriented cell tool-microcarrier gene chip, which is characterized by the following: augmentating promoter starting target to connect biotin; connecting magnet microparticle and fluorescent material on the nucleic acid probe; crossing with single-chain of target nucleic acid; separating and purifying target nucleic acid single-chain-probe; adopting high-polymolecule microparticle of clad biotin-proof protein as microcarrier; connecting target nucleic acid single-chain-probe; adopting double probe-sandwich method to test nucleic acid single-chain.

The invention relates to the field of detection in clinical immunology, in particular to a fluorescent immune chromatographic test strip for quantitively detecting troponin I and a preparation method thereof. The test strip provided by the invention comprises a bottom plate, sample absorbing pads attached to the bottom plate and staggered to each other sequentially, a labeled antibody pad, a coating film and a water absorbing pad. The labeled antibody pad is a troponin monoclonal antibody pad I coated with a fluorescent micro-spherical label and a troponin monoclonal antibody pad II coated with a biotin label for identifying different epitopes. The coating film is provided with a detection strip and a quality control strip. Avidin is fixedly arranged on the detection strip. A rabbit antimouse IgG antibody is fixedly arranged on a quality control line. By improving the test strip, a biotin-avidin amplifying system and a fluorescent immune chromatographic technology are introduced into detection of troponin I. Combined with a fluorescent detector, individual quantitive detection of troponin I is realized, therefore, extreme convenience is provided for clinical use.

The invention discloses a test strip for detecting aflatoxin B1 or M1 by utilizing an aptamer. The test strip for detecting the aflatoxin B1 or M1 by utilizing the aptamer, provided by the invention, comprises a sample absorption pad, a marker pad, a reaction film and a water absorption pad, wherein the marker pad is coated with a detection probe; the detection probe is an aflatoxin B1 aptamer marked by fluorescein; the nucleotide sequence of the aflatoxin B1 aptamer is sequence 1; the reaction film comprises a detection region and a quality control region; the detection region is coated with a conjugate formed by an aflatoxin B1 hapten and a carrier protein; and the quality control region is coated with a quality control probe, and the quality control probe is a conjugate formed by avidin conjugation probe marked aflatoxin B1 complementary single strand DNA (Deoxyribose Nucleic Acid)) molecules. The test strip for detecting the aflatoxin B1 or M1, provided by the invention, has the advantages of high sensitivity, accuracy in quantifying, strong specificity, simplicity and convenience, and short detection time.

The invention discloses a test strip for detecting HIV antibodies in spittle and a preparation method thereof. The test strip comprises a sample pad, a fiberglass film, a nitrocellulose film and absorbent paper, wherein the fiberglass film is tightly connected with one end of the sample pad and contains colloidal gold particle markers; the nitrocellulose film is tightly connected with the other end of the fiberglass film; the absorbent paper is tightly connected with the other end of the nitrocellulose film; the sample pad, the fiberglass film, the nitrocellulose film and the absorbent paper are all arranged on a base plate; the nitrocellulose film comprises a detection area coated with HIV recombinant antigens and a control area coated with goat anti rabbit antibodies; and the colloidal gold particle marker comprises a colloidal gold particle-avidin-biotin-antihuman IgG antibody composite micro-signal amplification system, and colloidal gold marking rabbie IgG antibodies. Due to the adoption of the avidin-biotin micro-signal amplification system, the test strip amplifies signals of the target antibodies, improves detection sensitivity and avoids false negative or detection omission caused by too weak signals.

Methods for delivering a biologically active molecule into a cell by linking a molecule to the cell surface, wherein the molecule can act as a surface receptor, then complexing the biologically active molecule with a ligand for the surface receptor, and finally contacting the biologically active molecule-ligand complex with the cell surface are disclosed. Delivery of any biologically active molecule, e.g. proteins, enzymes, nucleic acids, hormones, nucleic acids, and oligonucleotides, is contemplated. The use of biotin or biotinylated antibodies as the surface receptor is disclosed. The use of PEI and PEI-avidin conjugates complexed with oligonucleotides for delivery into a directly or indirectly biotinylated cell surface, along with the PEI-avidin-nucleic acid compositions, are disclosed. Primary and cultured cells with a covalently linked surface receptor molecule, such as biotin, on their surfaces are also disclosed.

The invention relates to novel streptavidin binding peptides.

The invention relates to immunoconjugates of formula: A-B-(C)n where B may be present or absent, A is a specific binding protein such as an antibody or an antibody binding fragment, or a ligand binding to a receptor present on target cells B comprises at least one molecule to which "A" and "C" bind, such as an avidin/streptavidin complex, "C" is an MHC molecule, and "n" is a whole number ranging from 1 to 10. The conjugates provide the exquisite binding specificity of antibodies, combined with an ability to stimulate cytotoxic T cells to identify and to destroy cells on which the conjugate is bound and oligomerized. The conjugates are useful both therapeutically and diagnostically.

The present invention is directed to immunoassays for detecting one or more target analytes in a fluid sample wherein the detection reaction occurs on a solid support and involves an amplification system. In particular, the invention is directed to making and using a test device having at least one site for detecting the presence of at least one target analyte, wherein a conjugate comprising dextran-polystreptavidin is immobilized at the test site(s) as a capture reagent for a complex containing the target analyte.

The invention provides for polynucleotides and vectors comprising at least two tag sequences. The invention also provides for polynucleotides and vectors comprising a streptavidin binding peptide sequence and a calmodulin binding peptide sequence. The invention also provides for polynucleotides and vectors wherein a gene of interest is fused in frame to at least two tag sequences, for example, a streptavidin binding peptide sequence and a calmodulin binding peptide sequence. The invention also provides for the chimeric proteins encoded by these polynucleotides. The invention also provides for methods of using the polynucleotides of the invention for detecting and/isolating protein complexes or identifying a binding partner for a protein of interest.

Magnets and magnetic particle-labeled reagents are used to capture and/or release magnetic particle-tagged entities for immunohematology diagnostic testing purposes, especially tests performed in blood banking. The magnetic tagged entities may be tagged antibodies, tagged blood cells, tagged universal binding partners, especially tagged lectins and tagged Coombs reagent, and other binding agents such as biotin-avidin, Protein A or G, ligands and their receptors and the like. Separation of unbound material from bound material is effected through the use of one or both the magnetic field effect on the magnetic labeled reactants and the density gradients of layers of an assay construct. Constructs such as chromatographic strip lateral flow format, and liquid phase reactions in suitable vessels with end point determinations that do not require centrifugation to detect reacted entities. Readable labels such as enzymes, fluorophors, chemiluminescent materials, radioactive isotopes, and other labels may be attached to Coombs reagent to provide a readable product of the Coombs reagent with any antibody participating in the assay.

The invention provides a broad-spectrum nucleic acid aptamer capable of identifying lipopolysaccharides of different Gram-negative bacterium sources. The broad-spectrum nucleic acid aptamer is obtained by directed screening on the basis of the capture-SELEX technology of label-free target molecules and immobilized nucleic acid libraries. A directed screening method of the broad-spectrum nucleic acid aptamer includes: using mouse salmonella typhi lipopolysaccharides as the unique target, using a biotin-avidin effect to fix random oligonucleotide libraries to Fe3O4 magnetic nano particles wrapped by avidin through biotinylated short complementary chains, performing incubation, separation, amplification, digestion single chain preparation, cloning sequencing and the like, adding complete active bacteria of salmonella and escherichia coli to serve as directed molecules to perform directed screening when the libraries are enriched to a certain degree, and one broad-spectrum nucleic acid aptamer capable of identifying four kinds of lipopolysaccharides is obtained through 15 rounds of repeated screening. The nucleic acid aptamer is applicable to the analysis and detection, separation and enriching, toxicity neutralizing and the like of the lipopolysaccharides in aspects of drinking water, food or clinical medicine and the like.

The invention discloses a quantitative detection kit for exon mutation of epidermal growth factor receptor (EGFR) relevant to lung cancers, which comprises a primer for amplifying exons of EGFR genes 18, 19, 20, 21, a sequencing primer and a magnetic bead marked by avidin. The invention also discloses a preparation method and a using method of the kit. The detection method in the invention not only has high sensitivity so that 1% of mutation can be detected, but also has visual result and simple, accurate and rapid interpretation, greatly reduces the false negative rate of the detection result and avoids invalid targeted medicine selections of clinical patients, thereby saving valuable treating time for the patients and improving the life quality of the patients.

The invention discloses an adenosine detecting method based on a micro-fluidic chip and a nucleic adapter technology. Biotin-modified adenosine nucleotide adapter and biotin-modified casein are fixed on the surface of an avidin-modified microsphere to form a functional microsphere through a biotin-avidin combining method; capture probes modified with horseradish peroxidase and sulfydryl are modified on nanometer particles as signal marks; functional nanometer particles flow to a micro-fluidic microsphere array to detect a detection area of a chip and hybrid with a microsphere array; after elution, an adenosine solution flows to be incubated with hybridized microspheres; a peroxidase substrate solution flows in; biotinylated tyramine is combined with the casein on the surface of the microsphere; the avidin-marked quantum dot flows in after elution; qualification and quantification are carried out on the adenosine by calculating a ratio of a fluorescence amount of the microsphere surface after adenosine inflows and a fluorescence amount of the microsphere surface before the adenosine inflows. The adenosine detecting method provided by the invention can be used for detecting and analyzing a target at high sensitivity, so that the specific and accurate quantitative analysis of the adenosine in a serum sample is realized.

The invention discloses a sepsis early diagnosis liquid chip which mainly includes the following components: microsphere coated with PCT capturing antibody, microsphere coated with CRP capturing antibody, microsphere coated with IL-6 capturing antibody, microsphere coated with Neopterin capturing antibody, these microspheres have codes with different colors; biotin-labeled test antibody; avidin-linked phycoerythrin. The invention sepsis early diagnosis liquid chip has advantages of high detection efficiency, a small amount of sample, high specificity and high sensitivity. And at the same time, the invention can test four kinds of specific markers of sepsis simultaneously, improve sensitivity and specificity of sepsis early diagnosis, distinguish sepsis caused by bacterial and viral, judge severity and poor prognosis of sepsis and monitor continuously for judging reflection of patient to certain kind of treatment.

The invention discloses a method for detecting a Miltenberger blood group antibody. The method comprises the steps of coupling nano magnetic beads with avidin to form avidin magnetic beads; coupling the avidin magnetic beads with a multipeptide antigen with a biotin-modified tail end, and closing non-coupled sites to obtain immune magnetic beads; uniformly mixing the immune magnetic beads with a detection sample, then performing incubation and washing, adding fluorescence labeled second antibody or enzyme-labeled second antibody, performing incubation and washing, and measuring a result. In the mode, the method for detecting the Miltenberger blood group antibody based on nano magnetic bead immunoassay is low in operation difficulty and is simple and convenient to operate, can be used for simultaneously detecting complete antibodies and incomplete antibodies; the detection process is short in time, and the result is easy to judge; automation is easily realized, and the detection result is accurate; in combination with a detector, semi-quantitative or quantitative detection can be realized; clinical safe, effective and scientific blood transfusion can be guaranteed.

The invention relates to a double-antibody biotin-Avidin ELISA (enzyme-linked immuno sorbent assay) detection kit for cattle viral diarrhea virus antigen and an application method thereof. The kit comprises washing liquid for ELISA detection, developing liquid, stopping liquid, Streptavidin-HRP, positive control and negative control and is characterized by further comprising an ELISA plate coating cattle viral diarrhea virus single antibody 3D8 and a cattle viral diarrhea virus single antibody 3F9 marked by biotin. The detection without cross reaction is performed by using the kit, thereby being capable of preventing leak detection caused by low titer in the antibody and having high specificity; a biotin-affine sensitizer is used for amplification, thereby increasing the flexibility, improving the detection rate, and simultaneously reducing the amount of second antibody; and the kit is suitable for being used widely.

The invention discloses novel coronavirus rapid detection test paper and a detection method. The novel coronavirus rapid detection test paper is composed of a sample pad, a colloidal gold pad, a reaction color development area, a water absorption area and a supporting plate; the sample pad and the water absorption pad are arranged on the supporting plate and located on the two opposite sides of the supporting plate respectively, and the sample pad is suction filter paper or a glass fiber membrane and used for bearing an object to be detected; a nitrocellulose membrane is fixed on the supporting plate, and the absorbent pad is absorbent paper; through double binding of a novel coronavirus antibody and a receptor ACE2 protein of a virus, a coronavirus protein antigen is specifically capturedand bound by adopting double enzyme-linked immunosorbent assay; the ACE2 antibody in the test paper reaction color development area is combined with biotin, avidin is connected with horse radish peroxidase, and through a biotin-avidin system, rapid judgment can be achieved through chemical color development, and the virus content can also be accurately detected through a microplate reader.