81 results about "Sandwich immunoassay" patented technology

Methods and apparatus are provided for assaying cell samples, which may be living cells, using probes labeled with composite organic-inorganic nanoparticles (COINs) and microspheres with COINs embedded within a polymer matrix to which the probe moiety is attached. COINs intrinsically produce SERS signals upon laser irradiation, making COIN-labeled probes particularly suitable in a variety of methods for assaying cells, including biological molecules that may be contained on or within cells, most of which are not inherently Raman-active. The invention provides variations of the sandwich immunoassay employing both specific and degenerate binding, methods for reverse phase assay of tissue samples and cell microstructures, in solution displacement and competition assays, and the like. Systems and chips useful for practicing the invention assays are also provided.

Methods and apparatus are provided herein for assaying biological samples using probes labeled with composite organic-inorganic nanoparticles (COINs) and microspheres with COINs embedded within a polymer matrix to which the probe moiety is attached. COINs are Raman-active nanoparticles made up of aggregated primary metal crystal particles with Raman-active organic compounds adsorbed on the surface in the junctions of aggregated primary metal crystal particles or embedded in the crystal lattice of the primary metal particles. Since COINs intrinsically produce SERS signals upon laser irradiation, COIN-labeled probes are particularly suitable in a variety of methods for assaying biological molecules, most of which are not inherently Raman-active. The invention provides variations of the sandwich immunoassay employing both specific and degenerate binding, methods for reverse phase assay of tissue samples and cell microstructures, in solution displacement and competition assays, and the like. Kits and chips useful for practicing the invention assays are also provided.

The invention relates to a disposable multi-channel electrochemical immunosensor with high sensitivity. A prussian blue composite, nanogold and a capture antibody are assembled layer by layer on a disposable printing electrode array to obtain a multi-channel immunosensor. Enzyme and secondary antibody in great proportion are assembled on a carbon nano tube loading gold nanoparticles and a novel glucose oxidase functional nano composite probe is designed for sandwich immunoassay. The nano composite probe is combined with the multi-channel immunosensor to realize double signal amplification and high sensitive immunodetection of protein. The prussian blue, as electronic transmission media, catalyzes and reduces hydrogen peroxide generated by glucose oxidation under the catalysis of glucose oxidase on oxygen so as to obtain current signal. The method avoids the interference of dissolved oxygen in the detection solution and deoxidization is not required in process of amperometric detection. The invention has the advantages of wide detection concentration range, good repeatability, accurate results and the like and has a certain clinical application value.

The present invention provides matched antibody pairs for the specific detection of one or more of the four dengue virus serotypes in a biological sample that may contain one or more of such dengue virus serotypes. Each matched antibody pair is capable of detecting not more than one serotype of dengue virus NS1 protein that may be present in the sample and will not cross react with other serotypes that may be present in the sample. Multiple matched pairs may be used to detect one or more dengue virus serotypes that may be present in a sample. Such matched pair antibodies, facilitate the development of confirmatory in vitro diagnostic tests such as sandwich immunoassays, that detect and distinguish the presence of one or more dengue virus serotypes in a biological sample, preferably a sample derived from human subject. The invention also provides kits comprising the matched antibody pairs of the invention and methods for using the kits for immunoassays for the specific detection of one or more serotypes of dengue virus in a patient population. The present invention also provides monoclonal antibodies specific for the NS1 protein of dengue virus and therapeutic compositions and methods for treating dengue virus infection.

A prerequisite of proteomics is the ability to quantify many selected proteins simultaneously. Fluorescent sandwich immunoassays on microarrays hold appeal for such studies, since equipment and antibodies are readily available, and assays are simple, scalable and reproducible. To attain adequate sensitivity and specificity, however, a general method of immunoassay amplification is required. Coupling of isothermal rolling circle amplification (RCA) to universal antibodies can be used for this purpose: RCA on a synthetic DNA circle is initiated by a complementary oligonucleotide attached to an anti-biotin antibody; single-stranded RCA product remains attached to the antibody, and is detected by hybridization of complementary, fluorescent oligonucleotides. 51 cytokines were measured simultaneously on microarrays with signal amplification by RCA with high specificity, femtomolar sensitivity and 4 log quantitative range. This cytokine microarray was used to measure secretion from human Dendritic cells (DCs) induced by lipopolysaccharide (LPS) or tumor necrosis factor-alpha (TNF-(alpha). Rapid secretion of inflammatory cytokines such as MIP-1beta, IL-8, and IP-10 was induced by LPS. Eotaxin-2 and I-309 were found to be induced by LPS, and MDC, TARC, sIL-6R, and sTNF-RI were found to be induced by TNF-alpha. Since microarrays can accommodate ~1000 sandwich immunoassays of this type, a relatively small number of RCA microarrays appears to offer a tractable approach for proteomic surveys.

A method for determining the contents of a biological marker and DNA through a direct-reading portable glucometer is characterized in that a glucose molecule embedded carrier liposome, hollow metal ball, porous carbon ball, porous silicon ball or polymer is introduced into the surface of a sensor as a composite marker through a sandwich immunization reaction or a DNA reaction, so the detection of the biological marker or DNA is converted into the detection of a final product glucose, the contents of the biological marker and DNA for detection are in direct proportion to the content of the embedded glucose according to the sandwich immunization analysis principle, and the contents of the biological marker and DNA can be obtained by detecting the concentration of glucose through the glucometer. The glucometer is developed into a portable and universal biological marker and DNA tester, and the glucometer detection technology based biological marker and DNA analysis new method is constructed, and can be used for the real-time, online, simple and sensitive determination of various biological markers and DNA. An apparatus used in the method is simple, so the analysis cost is low.

A method for detection and/or quantification of cardiac troponin I (cTnI) in a sample derived from an individual's blood, the method being based on a sandwich immunoassay employing at least two capture antibodies and at least one tracer antibody, in which a first capture antibody is directed to the N-terminal part of cTnI, to the C-terminal part of cTnI or to the part of the cTnI midfragment, which is slightly affected by the interfering factor, and a second capture antibody is directed to another of these parts, and a tracer antibody is directed to the N-terminal part of cTnI, to the C-terminal part of cTnI or to TnC, which is complexed with cTnI.

The invention relates to a high sensitive and jettisonable multicomponent chemiluminescent imaging immunosensor. The immunosensor is prepared by: constructing a 4*12 array on a silanized glass slide by a screen printing technique, and coating the array points with different capture antibodies to construct a jettisonable multicomponent immune sensor array; immobilizing biotinylated capture DNA and multiple G-quadruplex sequence repeat signal DNA on gold nanoparticle surfaces simultaneously, combining G-quadruplex signal DNA with heme to form DNA enzyme so as to prepare a multilayer DNA enzyme functionalized gold nanoparticle probe; and based on sandwich immunoassay, forming a sandwich immune complex on the sensor array, carrying out biotin-avidin reaction, labeling different immune complexes with the multilayer DNA enzyme functionalized gold nanoparticle probe; and making use of the peroxidase characteristics of DNA enzyme to catalyze reaction between chemiluminescent substrate H2O2-luminol to obtain a sensitive chemiluminescent signal, thus realizing high sensitive image immunoassay of a variety of protein. The immunosensor has the advantages of simple design, low cost, high sensitivity, high throughput and good repeatability, etc., and has certain clinical application value.

The present invention relates to a method for rapid immunochromatographic detection of a target in a sample by double sandwich immunoassay detection, wherein the target is an antibody and/or an antigen, using different colloidal gold conjugates conjugated with a first and a second specific antibody or antigen and with at least one oligonucleotide and its at least one complementary oligonucleotide and/or at least one non-specific antibody and its related non-specific antigen, to a rapid immunochromatographic detection device, to uses of the method for detecting diseases or specific conditions, and to a method for the manufacture of the device as well as to a kit which comprises the device.

The invention relates to the field of analysis and testing, and an in-vitro sandwich immunoassay process with magnetic separation for detecting alpha fetoprotein is built. The in-vitro sandwich immunoassay process is that a sandwich immune compound with a magnetic separation characteristic is obtained by catching an alpha fetoprotein antigen and a signal probe sandwich fixed by a quantum dot through a magnetic probe. The in-vitro sandwich immunoassay process for detecting the alpha fetoprotein builds an immunosensor to implement the detection of a target substance. The built immunosensor comprises a substrate electrode and modifies a prepared magnetic sandwich immune compound on the surface of the substrate electrode; and the relative electrogenerated chemiluminescent signals are different due to the different quantities of quantum dots relative to the alpha fetoprotein antigens with the different concentrations, so that the quantitative analysis of the alpha fetoprotein can be implemented. The in-vitro sandwich immunoassay process based on magnetism provided by the invention is good in anti-interference performance; and the detection method of the alpha fetoprotein is easy, the sample preprocessing is simple, and the detection and the analysis of content of the alpha fetoprotein in a serum sample with high flexibility can be adapted.

The invention provides a quantitative determination kit for human epididymis secretory protein 4 (HE4), which is applicable to a full-automatic chemiluminescence immunoassay analyzer, in particular relates to a preparation process of a kit for quantitatively detecting the concentration level of HE4 in human serum by adopting a dual-antibody sandwich acridinium ester-marked tubular chemiluminescence method. The kit adopts the dual-antibody sandwich immunoassay and utilizes a chemiluminescence magnetic microsphere immune technology, magnetic microspheres which are coated with anti-HE4 antibodies are specifically combined with the HE4 in a standard product/sample in a reaction cup and then react with another anti-HE4 antibody marked by the acridinium ester to form an immune complex, and the immune complex has the acid-alkali chemical reaction in a pre-trigger solution and a trigger solution, so that relative light unit (RLU/s) of the chemiluminescence reaction can be measured; the content of the HE4 in the standard product/sample is in direct proportion to the relative light unit (RLU/s) measured by an optical system, and the content of HE4 in a serum sample can be quantitatively measured by virtue of standard curve fitting. The quantitative determination kit has advantages of high sensitivity, high specificity, good stability, simplicity and convenience in operation, low cost and the like.

An improved double antigen sandwich immunoassay method aims to lower the false positive rate of the prior double antigen sandwich immunoassay method and improve the specificity of detection. The method can be applied to various detection methods such as rapid diagnosis, enzyme linked immune detection, chemiluminescent detection, and the like through adding an antihuman IgG monoclonal antibody or polyclonal antibody in a reaction system of the double antigen sandwich immunoassay method according to a certain proportion to participate in detecting. Compared with the prior double antigen sandwich immunoassay method, the double antigen sandwich immunoassay method of the invention remarkably lowers the detection background and the false positive rate and greatly improves the specificity.

The invention provides a sandwich immunoassay method comprising steps of, (a) forming a complex of an antigen and a first antibody by contacting the antigen with the first antibody which recognizes the antigen and is labelled by a detectable labelling substance; and (b) fixing the complex formed in the step (a) to a solid phase by using a second antibody which recognizes the antigen and is capable of binding to the solid phase, as well as a method for detecting an antigen in an analyte by using a method of sandwich immunoassay.

The invention relates to an automatic bovine cell factor chemiluminescence immunoassay detection method based on magnetic particles. Due to a sandwich immunoassay method, a magnetic ball serves as a fixed carrier of an antibody, and flow injection is combined to be applied to chemiluminescence analysis, so that the high-sensitivity automatic bovine cell factor chemiluminescence immunoassay detection method is built. An immunosensor is manufactured by activating the magnetic ball with the carboxyl, then covalently connecting the antibody to the surface of the magnetic ball and closing residual active sites; when being applied to detection of bovine cell factors, the immunosensor is fed into an immune micro reactor after being mixed with an antigen and the antibody which is labeled with horseradish peroxidase; the immunosensor is incubated on line to form a sandwich compound, and the sandwich compound is fed into a chemiluminiscence substrate; a luminous signal is immediately acquired, so that quick detection can be realized. The automatic bovine cell factor chemiluminescence immunoassay detection method has the characteristics of short analysis time, simplicity in operation, high specificity, high sensitivity and the like and can be used for quantitative detection of the bovine cell factors and researches on immunomechanisms of the bovine cell factors.

A sandwich immunoassay is disclosed that provides simple to perform yet sensitive identification of analytes in samples. All assay constituents needed (except analyte to be detected) for one assay are dried. Upon reconstitution with sample, a 10 to 15 minute incubation gives a rapid and convenient detection assay capability. The method incorporates the capture of antigen to an immobilized capture antibody. A labeled reporter antibody with the molecule, binds to the antigen to form an immunocomplex capable of generating a detectable signal.

The invention discloses a disposable nanometer electrogenerated chemiluminescence two-component immune sensor and a preparation method thereof. A monothiol compound and a bisthiol compound wrapped QDs electrogenerated chemiluminescence potential difference distinguish and ITO electrode space distinguish are used to achieve object detection. The sensor has a three-electrode structure; Ag / AgCl or saturated calomel electrode is used as a reference electrode, Pt electrode is used as an auxiliary electrode, and two pieces of modified ITO conductive glass capable of specifically identifying the two components are placed back to back as a working electrode for the two-component immune sensor; and an object to be measured is crosslinked to the surface of the working electrode by a sandwich immunoassay reaction, and finally crosslinked with horseradish peroxidase.

A method of enhancing fluorescence emission in a fluorophore-mediated sensing, biosensing, imaging, and bioimaging. An example of biosensing is a fluorophore-mediated sandwich immunoassay with a 1° monoclonal antibody against a target analyte and a fluorophore-linked 2° monoclonal antibody, exposing the immunoassay to an enhancing agent, applying excitation light to the immunoassay, and measuring an emission signal from the immunoassay.

The invention relates to a streptavidin functionalized semiconductor nano material-based tumor marker electrochemical immunosensor and a preparation method thereof. The immunosensor is prepared by the following steps: firstly, synthesizing or screening the semiconductor nano structure material with excellent performance, carrying out bio-functionalization by using the streptavidin, and then specifically combining with a biotinylation antibody. The prepared sensor is incubated in a mixed solution containing an enzyme-labeled antibody and an antigen, thionine and hydrogen peroxide are taken as enzyme reaction substrates, and the tumor marker is detected by using a sandwich immunoassay method. An ampere response of an electrode is increased along with an increase of antigen concentration in an incubation solution. The detection method is high in sensitivity, low in detection limit, and good in reproducibility and stability, and can be applied to quantitative determination of the tumor marker in serum.

The present disclosure describes two matched antibody pairs for use in a sandwich immunoassay for detecting and quantifying soluble PD-L1 in liquid samples, as well as an electrochemiluminescence sandwich immunoassay that has been optimized and validated with one of the matched pairs.

Monoclonal antibodies having a high affinity for human calcitonin, particularly monoclonal antibodies suitable for a sandwich immunoassay are disclosed. Also disclosed are hybridomas producing said monoclonal antibodies and a sandwich immunoassay utilizing said antibodies for determining human calcitonin in blood.

Immunoassays useful for detecting free beta2-microglobulin in a sample containing beta2-microglobulin/beta2-microglobulin associated protein complexes are provided. Also provided are a sandwich immunoassay and a competition immunoassay for detecting free beta2-microglobulin in a sample containing MHC monomers or MHC tetramers. Kits for performing such immunoassays also are provided.