423 results about "Nonspecific binding" patented technology

An electrochemical immunosensor system with reduced interference, comprising: a first immunosensor that generates an electrochemical signal based on the formation of a sandwich between an immobilized antibody, a target analyte and a labeled antibody, wherein a portion of the signal arises from non-specific binding of the labeled antibody in the region of the first immunosensor, and a second immunosensor that acts as an immuno-reference sensor and generates a signal that is the same as or predictably related to the degree of non-specific binding which occurs in the region of the first immunosensor, and has an immunocomplex between an immobilized antibody and an endogenous or exogenous protein that is in the sample and that is not the target analyte.

An electrochemical immunosensor system with reduced interference, comprising: a first immunosensor that generates an electrochemical signal based on the formation of a sandwich between an immobilized antibody, a target analyte and a labeled antibody, wherein a portion of the signal arises from non-specific binding of the labeled antibody in the region of the first immunosensor, anda second immunosensor that acts as an immuno-reference sensor and generates a signal that is the same as or predictably related to the degree of non-specific binding which occurs in the region of the first immunosensor, and has an immunocomplex between an immobilized antibody and an endogenous or exogenous protein that is in the sample and that is not the target analyte.

Compositions and methods of preparing functional thin films or surface coatings with low non-specific binding are described. The thin films contain specified functional groups and non-specific binding repellant components. The thin films are either covalently bound to or passively adsorbed to various solid substrates. The specified functional group provides specified activity for the thin film modified solid surfaces and non-specific binding repellant components significantly reduce the non-specific binding to the thin film modified solid surfaces. Non-specific binding repellant components do not affect specified functional group's activity in the thin films. In these methods, specified functional groups are anchored to the solid substrates through a spacer. Surface coatings are also described having both non-specific protein binding properties combined with functional groups for specific binding activity thereby providing surface coating that specifically recognize target proteins but limit binding to non-specific protein.

This invention provides methods and compositions, e.g., to reduce interference from non-specific binding sample constituents in a migration shift assay. Interference due to non-specific binding of sample constituents to an affinity substance (e.g., an affinity molecule or a conjugate of an affinity molecule and a charged carrier molecule) is prevented by, e.g., binding the constituents to charged polymers such as heparin sulfate. The present invention also provides methods to concentrate an analyte of interest with high concentration and to detect the analyte with high sensitivity, and further to optimize the reaction conditions for easily concentrating the analyte. Such objects of the present invention are attained, for example, by concentrating a complex of the analyte and a conjugate which is formed by contacting the analyte in a sample with an affinity molecule bound to a charged carrier molecule such as DNA.

Lateral flow assay devices and methods for detecting a first member of a specific binding pair in a sample which comprises a plurality of nonspecific binding pair members are adapted for two step determinations. In one embodiment, a two step lateral flow assay method for identifying IgE antibodies in a sample comprises applying a sample to a sample port of a device, wherein the device is adapted to deliver the sample to a lateral flow matrix having a plurality of IgE antigen species immobilized at respective positions at a first location The two step method further comprises allowing the sample to travel along the lateral flow matrix through the immobilized plurality of IgE antigen species to a second location downstream of the first location, applying liquid buffer to the lateral flow matrix to mobilize labeled reagent which is adapted to bind anti-IgE antibody and is dried on the lateral flow matrix at a location upstream of the delivery of the filtered sample to the lateral flow matrix, and allowing labeled reagent mobilized by the liquid buffer to travel along the lateral flow matrix through the immobilized plurality of IgE antigen species to a location downstream of the first location. Further embodiments comprise additional lateral flow immunoassay devices and methods for identifying IgE antibodies in a sample.

Arrays of protein-capture agents useful for the simultaneous detection of a plurality of proteins which are the expression products, or fragments thereof, of a cell or population of cells in an organism are provided. A variety of antibody arrays, in particular, are described. Methods of both making and using the arrays of protein-capture agents are also disclosed. The invention arrays are particularly useful for various proteomics applications including assessing patterns of protein expression and modification in cells.

Low molecular weight siloxane materials having one functional group are provided which have reduced tendency to form phase separated domains after polymerization. Two classes of siloxane materials are included: (1) symmetric siloxane macromonomers containing at least two monomer termini and one polymerizable functional group which is equidistant from the termini, and (2) assymetric siloxane macromonomers having at least one polymerizable functional group terminus and at least one oxygen-containing polar hydrophilic terminus selected from the group consisting of hydroxyl, ether, and polyether. Symmetric siloxane macromonomers having hydroxyl termini are useful for forming biocompatible materials, such as for contact lenses, tissue regeneration scaffold polymers, and coatings to reduce non-specific binding of proteins.

Described herein are systems and methods for the detection of and / or determination of a measure of the concentration of analyte molecules or particles in a fluid sample. In some cases, the systems and methods employ techniques to reduce or limit the negative effects associated with non-specific binding events. Certain methods of the present invention involve associating the analyte molecules at least a first type of binding ligand and at least a second type of binding ligand, and spatially segregating the analyte molecules into a plurality of locations on a surface. The presence of an analyte molecule at or in a location may be determined by determining the presence of both the first type of binding ligand and the second type of binding ligand.

The present invention provides materials, methods, and kits for reducing nonspecific binding of molecules to a surface, particularly in a solid phase material, and more specifically a solid phase material that includes a hydrophobic portion, by contacting the solid phase material with a fluorinated nonionic surfactant comprising two or more fluorinated hydrophobic segments and one or more hydrophilic segments.

The present invention relates to the field of molecular diagnostics, and in particular to diagnostics based on a liquid crystal assay format. In particular, the present invention provided improved substrates and methods of using liquid crystal assays for quantitating the amount of an analyte in a sample. The present invention also provides materials and methods for detecting non-specific binding of an analyte to a substrate by using a liquid crystal assay format.

Spheroidal beads present an exterior surface of a hydrophilic hydrogel, which is an isocyanate-functional polymer that is polymerized by urethane bonds and cross-linked by urethane and urea bonds. Sequestering agents present at the surface are covalently bound to isocyanate groups or to intermediate linkers that are so bound. These beads allow sequestering agents to retain their native three-dimensional configuration, and as a result of such surface characteristics and hydrophilicity, they achieve highly effective capture of very small subpopulations of rare cells from bodily fluids or the like and very effectively deter nonspecific binding of other biomaterials present in such bodily fluid. They may be all-hydrogel spheroids or hydrogel-coated substrates.

Methods for substantially improved detection and analysis in nucleic acid hybridization assays are described. The methods provide the reliable estimation of background signal which derives primarily from nonspecific hybridization. The invention is useful in chemical, biological, medical and diagnostic techniques, as well as for drug discovery.

Metallic nanoparticles coated with a mixed monolayer with well defined thickness or length are prepared. The mixed monolayer comprises a capture coating component useful for the specific capture of materials and a shielding coating component for elimination of non-specific binding of materials to the capture component.

The present invention relates to the field of molecular diagnostics. In particular, the present invention provided improved substrates and methods of using liquid crystals and other biophotonically based assays for quantitating the amount of an analyte in a sample. The present invention also provides materials and methods for detecting non-specific binding of an analyte to a substrate by using a liquid crystal or other biophotonically based assay formats.

Methods and apparatus for evanescent light fluoroimmunoassays are disclosed. The apparatus employs a planar waveguide with an integral semicylindrical lens, and has multi-analyte features and calibration features, along with improved evanescent field intensity. A preferred embodiment of the biosensor and assay method has patches of capture molecules, each specific for a different analyte disposed adjacently within a single reservoir. The capture molecules are immobilized to the patches on the waveguide surface by site-specific coupling of thiol groups on the capture molecules to photo-affinity crosslinkers, which in turn are coupled to the waveguide surface or to a nonspecific binding-resistant coating on the surface. The patches of different antibodies are produced by selectively irradiating a portion of the waveguide surface during the process of coupling the photo-affinity crosslinkers, the selective irradiation involving a mask, a laser light source, or the like.

Methods for decreasing non-specific bindings of beads in dual bead assays and related optical bio-discs and disc drive systems. Methods include identifying whether a target agent is present in a biological sample and mixing capture beads each having at least one transport probe affixed thereto, reporter beads each having at least one signal probe affixed thereto, and a biological sample. Mixing is performed under binding conditions to permit formation of a dual bead complex if the target agent is present in the sample. The reporter bead and capture bead each are bound to the target agent. Denaturing the target agent and keeping it in the denatured form by use of a specialized hybridization buffer is also provided. A denaturing agent is guanidine isothiocynate. Methods further include isolating the dual bead complex from the mixture to obtain an isolate, exposing the isolate to a capture field on a disc, and detecting the presence of the dual bead complex in the disc to indicate that the target agent is present in the sample. The methods may further include selectively breaking up non-specific binding between capture beads and reporter beads employing a digestion agent. Also employed is a method for selectively breaking up non-specific binding between capture beads and reporter beads using a wash buffer containing a chemical agent. The methods are applied to detecting medical targets.

A method for isolating, from a mixture, a virus having a surface protein with a binding site for sialic acid is provided. The method involves contacting the mixture with mucin which has been linked to a solid support and washing the solid support to remove material from the mixture is non-specifically bound to the mucin-linked support. Thereafter, the specifically bound virus (e.g., AAV4 or AAV5) may be removed in a further washing step utilizing a concentrated slat or solution with low pH. Also described are pharmaceutical kits containing solid supports linked to mucin for use in isolating virus having a surface protein with a binding site for sialic acid, or detecting the presence of the virus in a biological sample.

A composition for enhancing differential staining of RNA, DNA and granules in a sample comprising cells contains a first fluorescent dye that can bind specific binding sites and non-specific binding sites in the sample. This first dye emits fluorescence at a first wavelength. The composition contains at least an additional component, which is a second non-intercalating dye in the composition that competes with said first dye for binding to the nonspecific binding sites, or a permeabilizing agent to enhance permabilization of the dyes into the cells, or both. The molar ratio of the second dye and the first dye is at least about 20:1.

A preferred embodiment biosensor is a multi-layer micro-porous thin film structure. Pores in a top layer of the micro-porous thin film structure are sized to accept a first molecule of interest. Pores in a second layer of the micro-porous thin film structure are smaller than the pores in the top layer and are sized to accept a second molecule of interest that is smaller than the first molecule of interest. The pores in the second layer are too small to accept the first molecule of interest. The pores in the top layer and the pores in the second layer are sized and arranged such that light reflected from the multi-layer micro-porous thin film structure produces multiple superimposed interference patterns that can be resolved. In preferred embodiments, the multi-layer micro-porous thin film structure is a porous silicon thin film multi-layer structure formed on a silicon substrate, such as a silicon wafer. Specific and nonspecific binding can be detected with biosensors of the invention. The position of peaks in the Fourier transform of the reflection spectrum and the shift in peak amplitudes can be used to determine the presence and quantity of targeted biological molecules of interest.

Arrays of protein-capture agents useful for the simultaneous detection of a plurality of proteins which are the expression products, or fragments thereof, of a cell or population of cells in an organism are provided. A variety of antibody arrays, in particular, are described. Methods of both making and using the arrays of protein-capture agents are also disclosed. The invention arrays are particularly useful for various proteomics applications including assessing patterns of protein expression and modification in cells.

A biomolecular sensor system includes an array of magnetoresistive nanosensors designed for sensing biomolecule-conjugated superparamagnetic nanoparticles. Materials and geometry of each sensor element are designed for optimized sensitivity. The system includes magnetic field generators to apply forces to superparamagnetic nanoparticles for 1) nanoparticle manipulation, 2) sensor magnetic biasing, 3) magnetic pull-off measurement for differentiation against non-specific association, and 4) removal of all particles from the sensor array surface.

Compositions and methods of preparing functional thin films or surface coatings with low non-specific binding are described. The thin films contain specified functional groups and non-specific binding repellant components. The thin films are either covalently bound to or passively adsorbed to various solid substrates. The specified functional group provides specified activity for the thin film modified solid surfaces and non-specific binding repellant components significantly reduce the non-specific binding to the thin film modified solid surfaces. Non-specific binding repellant components do not affect specified functional group's activity in the thin films. In these methods, specified functional groups are anchored to the solid substrates through a spacer. Surface coatings are also described having both non-specific protein binding properties combined with functional groups for specific binding activity thereby providing surface coating that specifically recognize target proteins but limit binding to non-specific protein.

Azlactone-functional supports are used to provide cell selection from a mixture such as bone marrow or peripheral blood having a desired target cell population. An azlactone-functional support is derivatized by covalently coupling to the support a biologically active substance that binds the target cells. A mixture containing the target cells is contacted with the derivatized support to bind the target cells to the biologically active substance, and unbound remaining mixture is removed from the support. Bound cells may be eluted from the support to obtain purified target cells. Biologically active substances include antibodies, lectins, proteins, antigens and avidin. The biologically active substance may directly or indirectly bind cells in the mixture. Indirect binding may be through a second, intermediary biologically active substance that is bifunctional. The azlactone-functional support is provided by incorporating an azlactone moiety into a base polymer support that has been selected by prescreening base polymer supports with a cell mixture to identify a base polymer support having minimal nonspecific binding of cells in the mixture.