163 results about "Competitive binding" patented technology

A method for quantitating vitamin D metabolites directly in blood plasma or serum, without the need for prior purification of the vitamin D metabolites, comprising a digestion of the serum proteins with a serine protease such as proteinase K and sequence of steps for inhibiting the proteinase K activity in the competitive binding analysis. The advantages of this method are its high accuracy over the whole range of physiologically relevant values and that it can be easily adapted for a fully automated analysis of serum and plasma samples.

Methods are provided for detecting, separating, isolating and quantifying contaminants in starting materials by separating the contaminant from the starting material using a bead coupled to an affinity moiety and quantum dot-labeling the contaminant. The contaminant is detected by the characteristic emission spectrum of the quantum dot. Also, competitive binding methods are provided wherein the starting material and a control material are contacted with a quantum dot coupled to an affinity moiety capable of binding the contaminant and a competitor complex. A decrease in the intensity of the characteristic emission spectrum of the quantum dot associated with the competitor complex from the starting material as compared to that of the control material is indicative of the presence of the contaminant in the starting material.

The invention relates to a latex enhanced immunoturbidimetry kit for the detection of asymmetric dimethylarginine content. Specifically, the invention relates to a latex enhanced immunoturbidimetry kit for the detection of asymmetric dimethylarginine (ADMA) content in human blood samples. The kit comprises a mouse anti-human monoclonal antibody solution, an ADMA-human Serum albumin complex crosslinked latex particle expansion and an ADMA calibrator. According to the method, by the utilization of competitive binding of free ADMA in blood and ADMA crosslinked on the surface of latex particles to ADMA monoclonal antibody, turbidity formed by the reaction between the ADMA-crosslinked latex particles and ADMA monoclonal antibody is reduced. Therefore, the content of ADMA is detected through the reduction degree of turbidity. The kit provided by the invention can be applied in a biochemical analyzer commonly-used in clinic, is convenient and rapid to operate and has strong specificity. Both sensitivity and detection range of the kit can satisfy clinic application needs.

A static fluid and a second fluid are placed into contact along a microfluidic free interface and allowed to mix by diffusion without convective flow across the interface. In accordance with one embodiment of the present invention, the fluids are static and initially positioned on either side of a closed valve structure in a microfluidic channel having a width that is tightly constrained in at least one dimension. The valve is then opened, and no-slip layers at the sides of the microfluidic channel suppress convective mixing between the two fluids along the resulting interface. Applications for microfluidic free interfaces in accordance with embodiments of the present invention include, but are not limited to, protein crystallization studies, protein solubility studies, determination of properties of fluidics systems, and a variety of biological assays such as diffusive immunoassays, substrate turnover assays, and competitive binding assays.

The present invention relates to a method for screening and identifying test compounds that bind to a preselected target ribonucleic acid ("RNA"). Direct, non-competitive binding assays are advantageously used to screen libraries of compounds for those that selectively bind to a preselected target RNA. Binding of target RNA molecules to a particular test compound is detected using any physical method that measures the altered physical property of the target RNA bound to a test compound. The structure of the test compound attached to the labeled RNA is also determined. The methods used will depend, in part, on the nature of the library screened. The methods of the present invention provide a simple, sensitive assay for high-throughput screening of libraries of compounds to identify pharmaceutical leads.

The present invention provides stabilized chemiluminescent formulations for use in in vitro diagnostics, including competitive as well as sandwich-type immunological assays. The stabilized assay system may be composed of two components, where the first component may contain a chemiluminescent organic compound, an enhancer, a homogenizing agent, and a suitable buffer with formulations having a pH range from about 7.2 to about 12, and optionally a solubilizing agent. The chemiluminescent system of the present invention is useful in immunoenzymatic analytical procedures, such as immunometric, competitive binding and sandwich type assays. In such immunoassays employing the chemiluminescent system of the present invention, the detectable light signal shows a proportional decay with time in the test samples and standards, so that the decay of the light emitted does not effect the concentration of the analyte measured over the entire analyte measurement range of the immunoassay. This allows accurate measurement of analyte concentrations in a test sample over extended periods of time.

A method for quantitating vitamin D metabolites directly in blood plasma or serum, without the need for prior purification of the vitamin D metabolites, comprising a digestion of the serum proteins with a serine protease such as proteinase K and sequence of steps for inhibiting the proteinase K activity in the competitive binding analysis. The advantages of this method are its high accuracy over the whole range of physiologically relevant values and that it can be easily adapted for a fully automated analysis of serum and plasma samples.

A sensor for the detection or measurement of a carbohydrate analyte in fluid comprises components of a competitive binding assay the readout of which is a detectable or measurable optical signal retained by a material that permits diffusion of the analyte but not the assay components, the assay components comprising: a carbohydrate binding molecule labelled with one of a proximity based signal generating / modulating moiety pair; and a carbohydrate analogue capable of competing with the analyte for binding to the carbohydrate binding molecule, the carbohydrate analogue being a flexible water-soluble polymer comprising: polymerized or co-polymerised residues of monomer units, the monomer unit residues bearing pendant carbohydrate or carbohydrate mimetic moieties and pendant moieties which are the other of the proximity based signal generating / modulating moiety pair.

The invention relates to a device for determining two or more respiratory parameters relating to an individual and a method for determining two or more respiratory parameters relating to an individual by means of the device. The disclosed device and method may be used in an individual suffering from pulmonary gas exchange problems relating to gas exchange of oxygen and / or carbon dioxide, e.g. a patient with chronic obstructive pulmonary disease. The device and method may also be used in a healthy individual or in an animal, e.g. for research experiments. The device has detection means for oxygen and carbon dioxide contents in inspired and expired gas and blood. The device is controlled by a computer with functionality for entering oxygenation, carbon dioxide and acid-base values from one or more blood samples from arterial, venous, central venous or mixed venous blood samples, and with the parameter estimation based on equations of gas exchange of both oxygen and carbon dioxide and equations describing the acid-base chemistry of blood potentially including the competitive binding of oxygen and carbon dioxide to hemoglobin.

A competitive binding assay is used to determine whether a non-nucleic acid molecule from a library of non-nucleic acid molecules binds to a target. The non-nucleic acid molecule competes with a labeled nucleic acid ligand for binding to the target which may be immobilized. Detecting displacement of labeled nucleic acid ligand from a complex of the labeled nucleic acid ligand and the target determines binding of the non-nucleic acid molecule to the target. The nucleic acid ligand may be immobilized and contacted with a labeled target to form a complex. Adding a non-nucleic acid molecule to the complex displaces labeled target from the complex, and detecting displacement of the labeled target determines binding of the non-nucleic acid molecule to the target. Labeled nucleic acid ligand or labeled target displaced from or remaining in the complex can be detected for detecting displacement. Nucleic acid ligands that bind to the target are identified by the SELEX method. The assay provides a high throughput screening method for determining whether a non-nucleic acid molecule binds to a target.

The invention provides a thio / oxo-naphthalimide compound and application thereof. The compound has a structure shown as a general formula I. The compounds are capable of realizing competitive binding and antagonism of Bcl-2 and Mcl-1 proteins in vitro and in cells so as to induce cell apoptosis, and refer to a type of apoptosis inducers and antitumor compounds with extremely high activities. In addition, the derivative designed based on the compound can serve as a bifunctional molecule and is capable of recognizing, separating, enriching and realizing fluorescence detection of Bcl-2 family proteins; or the derivative can serve as a PROTAC bifunctional complex for selectively degrading the Bcl-2 and Mcl-1 proteins in the cells, so that the level of the Bcl-2 family proteins in living cells is regulated. The structural formula is as shown in the specification.

The invention relates to a pesticide and veterinary drug multi-residue detection method based on a microarray detection chip. The method comprises the steps that a micromolecular pesticide and veterinary drug hapten is coupled with bovine serum albumin to prepare an immunizing antigen; a mouse is immunized by the immunizing antigen to prepare a corresponding pesticide and veterinary drug monoclonal antibody; a biochip sample application instrument for a monoclonal antibody acquisition probe performs sample application on an agarose modified slide solid phase carrier to prepare a multi-repeat monoclonal antibody acquisition probe microarray; the pesticide and veterinary drug hapten is coupled with ovalbumin to prepare a hapten-OVA (ovalbumin) couplet; a fluorescent molecule Cy3 is then used for labeling; sample liquid to be detected is incubated with the chip after mixed with a labeling detection antigen according to a certain concentration; a to-be-detected antigen in a sample and the corresponding labeling detection antigen are directly and competitively bound with the corresponding monoclonal antibody acquisition probe fixed on the chip; elution is performed under a certain condition; and a result is detected by a biochip scanner. The method can detect multiple pesticide and veterinary drug residues in the subsidiary agricultural product sample simultaneously, and is applicable to high-throughput, quick and accurate detection of drug residues in planting and culture production.

An outputs signal, v(t), is generated from a bioNEMs transducer and mixed with a reference signal and then filtered to generate a correlator output, r(t). The correlator output is detected to generate a signal u(t) and then determined whether the signal u(t) satisfies a predetermined threshold. If qualified, it is then decided whether the signal u(t) represents a predetermined type of interaction between a free ligand in a fluid in which the NEMS device is immersed and a receptor attached to the transducer. The threshold is the Neyman-Pearson criterion based on a predetermined probability of false detection, Pfa. The interaction may be binding of a free ligand to the receptor or releasing a bound ligand from the receptor by competitive binding with the free ligand. The step of detecting comprises detecting the envelope of the signal, r(t).

The invention relates to hydrogel and organogel sensors as well as their application to continuous analyte monitoring. The sensor can include a hydrogel or organogel matrix. Standard and inverse designed are provided. In one embodiment, the matrix can include a molecular recognition agent for an analyte (e.g., a glucose analyte), and a volume resetting agent that reversibly binds with the molecular recognition agent. Reversible crosslinks between the molecular recognition agent and volume resetting agent can change the volume of the matrix upon interacting with the analyte via a competitive binding process. In various embodiments, the invention provides a hydrogel-based glucose sensor and sensors for continuous glucose monitoring. The glucose sensor can be based on a glucose-responsive hydrogel with a volume linearly correlated with glucose concentrations, such as about 0.05-50 mM, under physiological conditions. The invention thus provides a blood glucose monitor suitable for use in clinical settings.

Disclosed is the invention to conduct immuno-adsorption of free 25(OH) vitamin D from blood or blood components, notably serum or plasma, after which the absorbed material is measured. A fluoro-alkyl surfactant is used to enhance the solubility of Vitamin D and allow the measurement of free Vitamin D. The invention thus employs a binding protein to absorb the free 25(OH) vitamin D. Thereafter the binding protein comprising the 25-OH vitamin D is subjected to a competitive binding assay with a labeled vitamin D compound, preferably radiolabeled, fluorescent labeled, luminescent labeled, biotin labeled, gold labeled or enzyme labeled. Alternatively the immunocaptured 25-OH vitamin D can be quantitated by mass spectrometry.

An outputs signal, v(t), is generated from a bioNEMs transducer and mixed with a reference signal and then filtered to generate a correlator output, r(t). The correlator output is detected to generate a signal u(t) and then determined whether the signal u(t) satisfies a predetermined threshold. If qualified, it is then decided whether the signal u(t) represents a predetermined type of interaction between a free ligand in a fluid in which the NEMS device is immersed and a receptor attached to the transducer. The threshold is the Neyman-Pearson criterion based on a predetermined probability of false detection, Pfa. The interaction may be binding of a free ligand to the receptor or releasing a bound ligand from the receptor by competitive binding with the free ligand. The step of detecting comprises detecting the envelope of the signal, r(t).

The invention provides a method of detecting surrogate markers for active tuberculosis in a serum sample. The surrogate markers are selected from serum mycolic acid antigen, serum anti-mycolic acid antibodies or both. The method includes the steps of combining the serum sample with a labelled monoclonal immunoglobulin antibody or fragment thereof to mycolic acids to produce a combined serum sample, the antibody or fragment thereof not substantially cross-reacting with cholesterol and the label being selected so that binding of the labelled antibody to immobilized mycolic acid antigen of mycobacterial origin produces a detectable signal and combining a blank sample with the labelled monoclonal immunoglobulin antibody or fragment thereof to mycolic acid to produce a combined blank sample. The method includes exposing both samples to immobilised mycolic acid antigen of mycobacterial origin or a synthetic analogue or analogues thereof so that the labelled immunoglobulin antibodies or fragments thereof in each sample bind to the immobilised antigen to produce detectable signals. If the surrogate markers are present, the signal produced by the blank sample will be stronger than that produced by the serum sample because of inhibition of binding of the labelled antibody in the serum sample arising from prior binding of the labelled antibody with the mycolic acid antigen in the serum sample or by competitive binding of serum anti-mycolic acid antibodies in the serum sample to the immobilised mycolic acid antigen or both.

Disclosed are immunomagnetic electrochemiluminescence assays for eukaryotic cells, particularly human cells. A competitive binding assay is disclosed which enables affinity measurements of antibodies specific for eukaryotic cell membrane proteins. Such an assay is particularly useful for verifying or measuring the affinity of therapeutic antibodies following chelate conjugation.

The invention provides a high-sensitivity chemiluminescence immunoassay kit, and a preparation method and application thereof, belonging to the technical field of clinical immunoassay. The high-sensitivity chemiluminescence immunoassay kit comprises a solid-phase vector directly coated with a capture molecule, a biotin-labeled marker molecule and luminescent substance-labeled streptavidin, whereinthe marker molecule is capable of binding to a target analyte in a to-be-detected sample, and the capture molecule is capable of specifically binding to the target analyte in the to-be-detected sample or is an analog of the target analyte in the to-be-detected sample; or the marker molecule is capable of competitively binding to the target analyte in the to-be-detected sample, and the capture molecule is capable of specifically binding to the target analyte in the to-be-detected sample. The kit provided by the invention is based on the structural characteristics of streptavidin; per mole of tetramer molecules can bind to four moles of biotin molecules, and strong affinity are formed between the tetramer molecules and the biotin molecules; and a cyclic amplification reaction process is constructed to realize signal amplification, so the sensitivity of the kit is improved.

The invention discloses a method for detecting the affinity of monoclonal antibodies of transmembrane proteins. The method mainly includes steps of 1), constructing stable cell strains with membrane protein high expression to guarantee the maximum right shift of positive combination peaks in FACS (fluorescence-activated cell sorter) assay; 2), labeling antibodies by the aid of fluorecein; 3), carrying out saturation binding assay; 4), carrying out competitive binding assay; 5), processing data. The method has the advantages that the affinity of the monoclonal antibodies of the transmembrane proteins can be effectively measured; radioactive isotopes can be omitted, accordingly, the method is high in safety and sensitivity and good in repeatability, stable and reliable detection results can be obtained, and the like.

The invention discloses a method for improving the structural stability of a biological material and the biological material. The method comprises the steps of soaking the biological material in an aqueous solution of tea polyphenol and metal ions, and adsorbing the tea polyphenol on hydrophobic sections of elastin fibers under the function of hydrogen bonds. In this way, the structural stabilityof elastin is improved, the metal ions and calcium ions conduct competitive binding to adsorb the tea polyphenol, and thus the calcification of the biological material is inhibited. By means of the method, the structural stability and anti-calcification performance of the biological material can be improved, and the service life of the biological material is potentially prolonged.

Disclosed is an invention in the field of conducting an immunoassay of 25(OH) vitamin D in blood or blood components, notably serum or plasma. The invention employs a perfluoro alkyl acid, or a salt thereof, to release 25(OH) vitamin D from vitamin D binding protein. Thereafter the binding protein comprising the 25-OH vitamin D is subjected to a competitive binding assay with a labeled vitamin D compound.

The invention discloses a method for detecting tetracycline (TET) based on a colloidal gold (AuNPs) chromatography test strip of aptamer. The method uses specific binding between colloidal gold and the aptamer and competitive binding capacity strength between the tetracycline and DNA (deoxyribonucleic acid) and the aptamer. The method comprises the following steps of synthesizing colloidal gold nanoparticles suitable for marking the aptamer; assembling and coupling the colloidal gold and the aptamer; assembling streptavidin with a DNA chain; preprocessing a sample pad and a gold pad; scribing lines on an NC membrane; assembling the test strip; detecting standard tetracycline; performing selectivity and specificity experiments; using the established colloidal gold test strip based on the aptamer to measure the tetracycline in a practical sample. The tetracycline detecting method provided by the invention has the advantages of having better selectivity and flexibility, being simple, economic and easy to operate and being more suitable for in-site quick detection.

The invention relates to a method for detecting mercury ion residue of a fluorescent signal conversion mechanism based on a nucleic acid aptamer structure. In the method, a mercury ion nucleic acid aptamer marked with a fluorescein molecule, and a complementary sequence marked with a quenching element are utilized to form a fluorescent detection system, wherein the mercury ion nucleic acid aptamer is a stem loop structure composed of 27-28 bases and owns a stem formed by covalent binding of the bases GGAC and GTCC; and the base sequence of the complementary sequence Q2 is shown in SEQ ID NO.1. The method for detecting the mercury ion residue by the fluorescent detection system comprises the following steps of: adding mercury ions with a serial concentration and a complementary sequence Q2 competitive binding nucleic acid aptamer; establishing a standard curve according to the change of fluorescent signals and determining the lowest detection limit and linear range; and then, carrying out marking detection on a sample to be detected and judging the content of the mercury ions in the sample according to the standard curve. The method disclosed by the invention has the advantages of rapidness, simplicity, high sensitivity and selectivity and less sample quantity demand, and is applicable to the detection of the mercury ions in the actual sample.

The present invention provides for an assay that identifies kinase inhibitors by employing fluorescence resonance energy transfer in a competition binding approach.

The invention belongs to the technical field of immunodetection and relates to a novel crytococcus neoformans GXM (glucuronoxylomannan) antigen immunodetection kit. The kit comprises an enzyme-labelled carrier coated with GXM, an anti-GXM polyclonal enzyme-labelled antibody and a GXM standard substance, wherein GXM is obtained from a novel crytococcus neoformans culture solution through extraction and purification; according to the kit, an enzyme-labelled plate is coated with GXM firstly, then a to-be-detected sample or a standard antigen and a coating antigen are subjected to competitive binding with limited antibody binding sites, then an enzyme and a substrate have a chromogenic reaction, and the concentration value of a to-be-detected antigen is calculated according to the detection result. The detection kit has better sensitivity, specificity, repeatability and stability, is higher in recovery rate of target compounds, can provide more accurate and reliable detection results, is convenient and easy to use and operate and provides an effective tool for clinical detection of GXM.

A competitive binding assay is used to determine whether a non-nucleic acid molecule from a library of non-nucleic acid molecules binds to a target. The non-nucleic acid molecule competes with a labeled nucleic acid ligand for binding to the target which may be immobilized. Detecting displacement of labeled nucleic acid ligand from a complex of the labeled nucleic acid ligand and the target determines binding of the non-nucleic acid molecule to the target. The nucleic acid ligand may be immobilized and contacted with a labeled target to form a complex. Adding a non-nucleic acid molecule to the complex displaces labeled target from the complex, and detecting displacement of the labeled target determines binding of the non-nucleic acid molecule to the target. Labeled nucleic acid ligand or labeled target displaced from or remaining in the complex can be detected for detecting displacement. Nucleic acid ligands that bind to the target are identified by the SELEX method. The assay provides a high throughput screening method for determining whether a non-nucleic acid molecule binds to a target.

The invention discloses a gold-labeled secondary antibody signal amplified SRP (surface plasmon resonance) immunosensing method for detection of atrazine. The method adopts antigen-antibody immunoreaction as the basic principle, an antigen or antibody is taken as a sensor sensitive recognition element, an indirect competitive technique and an SPR sensing technology are combined to detect the herbicide atrazine, an atrazine complete antigen (AT-OVA) is fixed on the surface of an SPR chip through a chemical bond, competitive binding with the antibody is carried out on the atrazine small molecules in a to-be-detected solution, a nanogold-labeled secondary antibody is added to perform signal amplification, the detection sensitivity is enhanced, the detection range is improved, and the signal amplified indirect competitive inhibition method is established. The lowest detection limit of the method is 0.72ng / mL, IC50 is 15.70ng / mL, and the detection range is 2.18-629.06ng / mL.