Abstract: A rapid immunochromatographic assay system is provided for measuring the amount of glycated albumin in a blood sample relative to the total level of albumin in the sample. The assay system is comprised of a disposable cassette that contains the test strips and testing reagents, and a measurement device that automatically reads, calculates and displays the test results over a period of time. The test cassette contains two test strips that are used to measure glycated albumin and total albumin respectively. The strips are contiguous beneath the single sample application well so that the same sample is tested simultaneously by both test strips. Part of the sample will migrate thru the glycated albumin test strip where it will react with the glycated albumin test reagents to yield a glycated albumin result, while part of the sample will migrate thru the total albumin test strip where it will react with the total albumin test reagents to yield a total albumin result.

Abstract: A latex reagent for analyzing adiponectin, comprising a suspension of latex particles carrying a substance which specifically binds to adiponectin, is disclosed. Further, a method for analyzing adiponectin, comprising (1) obtaining a biological liquid possibly containing adiponectin, and (2) bringing the biological liquid, while maintaining the state in which the biological liquid is obtained, into contact with a suspension of latex particles carrying a substance which specifically binds to adiponectin, and optically analyzing a degree of latex-particles-agglutination, is disclosed. According to the latex reagent and the method for analyzing adiponectin, a predilution or pretreatment of the biological liquid to be analyzed is not necessary. Further, the analysis can be performed rapidly and conveniently, and facilities therefor are not limited.

Abstract: Topiramate analogs have substituents at the sulfamate group, 9-position, or 10-position. Topiramate analogs may include immunogenic moieties to prepare anti-topiramate antibodies, or antigenic moieties for immunodiagnostic assays. Also, the topiramate analog can include tracer moieties for detecting the presence or amount of the analog during an immunodiagnostic assay. Additionally, the topiramate analogs can be used in immunodiagnostic assays to compete with topiramate for binding with anti-topiramate antibodies. Such an immunodiagnostic assay can be used for detecting the presence of topiramate in a sample obtained from a subject previously administered topiramate by the following: combining an anti-topiramate antibody and a topiramate analog with a sample to form a first composition; allowing any free topiramate from the sample and the topiramate analog to compete for binding with the antibody; detecting binding between the topiramate analog and the antibody.

Abstract: A flow-through assay for detecting the quantity of an analyte residing in a test sample is provided. The flow-through assay contains a porous membrane that is in fluid communication with probe conjugates that contain a specific binding member and a detectable probe. The porous membrane also defines a detection zone and a calibration zone. The calibration zone contains a polyelectrolyte substantially non-diffusively immobilized on the porous membrane. The polyelectrolyte is capable of generating a detectable calibration signal that can be readily compared (visually, quantitatively, and the like) to a detection signal to determine the amount of analyte in the test sample.

Abstract: Generally, the present invention relates to topiramate analogs that have substituents at the sulfamate group or at the 9-position or 10-position. The topiramate analogs can include immunogenic moieties that can be used to prepare anti-topiramate antibodies, or antigenic moieties that can be used in immunodiagnostic assays for topiramate. Also, the topiramate analog can include tracer moieties for detecting the presence or amount of the analog during an immunodiagnostic assay. Additionally, the topiramate analogs can be used in immunodiagnostic assays to compete with topiramate for binding with anti-topiramate antibodies.

Abstract: The invention relates to devices for performing single step assays for the determination of the presence or absence of an analyte in a liquid sample, and methods of determining the presence or absence of such analytes using such devices. Devices disclosed comprise a labeled analyte-binding reagent reversibly-immobilized on a non-porous solid material, which solid material is in physical contact with a dry porous carrier bearing an immobilized analyte-binding reagent. Also provided are quantitative assay devices.

Abstract: The present invention relates to a systematic process for the creation of functionally organized, spatially patterned assemblies polymer-microparticle composites including the AC electric field-mediated assembly of patterned, self supporting organic (polymeric) films and organic (polymeric)-microparticle composite films of tailored composition and morphology; the present invention further relates to the incorporation of said assemblies into other structures. The present invention also relates to the application of such functional assemblies in materials science and biology. Additional areas of application include sensors, catalysts, membranes, micro-reactors, smart materials. Miniaturized format for generation of multifunctional thin films. Provides a simple set-up to synthesize thin films of tailored composition and morphology.

Abstract: A method for performing an immunoassay is described. The method is particularly useful for detecting extracellular polysaccharide (EPS) and/or lipopolysaccharide (LPS) producing microorganisms. The method is particularly useful for detecting microorganisms which produce extracellular polysaccharides (EPS) also known as exocellular polysaccharides, capsule, and/or lipopolysaccharides (LPS). In a preferred method for detecting microorganisms which produce EPS, LPS, or both, the EPS and/or LPS is extracted from a sample with cetyltrimethylammonium bromide (CTAB) to produce molecular aggregates which are then preferentially bound to colored polystyrene latex particles over other components in the sample, and the bound EPS and/or LPS detected using a lateral flow immunoassay apparatus which has immobilized thereon antibodies specific for the EPS and/or LPS. The method can also be used to detect particular viruses, for example viruses of the potyviridae or tobamoviridae group.

Abstract: The invention provides a particle comprising a surface, wherein a portion of the surface is capable of emitting electromagnetic radiation and another portion of the surface is capable of emitting a differential electromagnetic radiation (either different intensity, different frequency or no radiation), and wherein the arrangement of said portions of the surface defines a spatially distributed code for identifying the particle. The invention also provides method of manufacturing a particle having an identifying code comprising providing a particle with a functionalized surface which comprises functional binding moieties and selectively removing a plurality of the functional binding moieties from the surface to create a pattern of functionalized and differentially-functionalized zones on the surface. Various liquid-based assay methods employing the particle of the invention and a kit comprising the particle of the invention are also disclosed.

Abstract: An immunological latex turbidimetry method for analyzing an antigen or antibody in a sample is disclosed, comprising steps of (1) bringing a sample which may contain the antigen or antibody to be analyzed into contact with a protease-treated albumin, and (2) bringing a mixture obtained in the above step (1) into contact with latex particles carrying an antibody or antigen specifically reacting with the antigen or antibody to be assayed, and analyzing a turbidity caused by a latex agglutination reaction. Also disclosed is an immunological latex turbidimetry reagent comprising (1) a first component containing a protease-treated albumin, and (2) a second component containing latex particles carrying an antibody or antigen specifically reacting with an antigen or antibody to be assayed.

Abstract: A test device and method for determining the presence or absence of one or more analytes in a fluid sample, the test device including a support or member bearing a mark thereon, and a matrix or member containing a capture zone. In operation, an observation area in the test device becomes transparent, thereby allowing the user to view a mark that is present on a support that is disposed beneath the observation area. Typically, the mark on the underlying support is configured as a minus (?) sign. In the absence of analyte in the sample, the test device presents a negative result as a minus (?) signal. In the presence of analyte in the sample, however, the mark operates in concert with a perpendicular test line on the observation area to present a positive result as a plus (+) signal that is visible to the user.

Abstract: A method of single parameter and multiparameter characterizing of cells, particularly immunophenotyping of cells, is provided. The method preferably uses antibody coated microspheres which are adapted to bind to specific types of cells. One or more sets of coated microspheres are added simultaneously or sequentially to a suspension of cells and bind the cells they are adapted to bind. Cells may bind to one or more microspheres. The suspension is then filtered to trap bead-cell complexes. The complexes are preferably stained and then examined to characterize the cells, preferably the cells bound to the microspheres. A kit and apparatus for performing the method are also provided.

Abstract: Rare cells are separated from a sample fluid by a positive selection or negative selection antibody by centrifuging in a tube containing a harvesting float. The harvesting float has an axial passage and a density to settle in the sample fluid and expand the layer of the target component. The positive selection antibody is preferably coupled to a particulate carrier, such as a microbead, to attach to the target component. The negative selection antibody forms a complex or conjugate with a contaminating component. In the positive separation, the particulate carrier is recovered in the axial passage of the float.

Abstract: In one aspect, an assay test strip includes a test label that specifically binds a target analyte and a control label that is free of any specific binding affinity for the target analyte and has a different optical characteristic than the test label. In another aspect, an assay test strip includes a test label that specifically binds a target analyte and at least one non-specific-binding label that is free of any specific binding affinity for the target analyte. Systems and methods of reading assay test strips also are described.

Abstract: An assay test strip includes a flow path, a sample receiving zone, a label, a detection zone that includes a region of interest, and at least one position marker. The at least one position marker is aligned with respect to the region of interest such that location of the at least one position marker indicates a position of the region of interest. A diagnostic test system includes a reader that obtains light intensity measurement from exposed regions of the test strip, and a data analyzer that performs at least one of (a) identifying ones of the light intensity measurements obtained from the test region based on at least one measurement obtained from the at least one reference feature, and (b) generating a control signal modifying at least one operational parameter of the reader based on at least one measurement obtained from the at least one reference feature.

Abstract: A method for determining the concentration of factor VIIa-antithrombin complexes is disclosed which has application to estimating the level of intravascular exposure of tissue factor, assessing patient risk for hypercoagulation or other coagulopathies, and monitoring patients for factor VIIa-antithrombin complexes over time which can reveal changes in risk for hypercoagulation or other coagulopathies and/or effectiveness of anticoagulant therapy. Antibodies suitable for use in an in vitro assay for determining the concentration of factor VIIa-antithrombin complexes and methods for making the same are also disclosed.

Abstract: An interactive system is provided with at least one active surface of plastic from monomers containing at least one structural element derived from a carbon dioxide (A), and at least one substance associated to a linker with at least one structural element (B) capable of establishing a hydrogen bond, and involving an interaction between the structural elements (A) and (B). The interactive system is suitable for presenting and eliminating substances in liquids.

Abstract: This invention provides solid phase specific binding lateral flow assay methods, devices and kits for quantitating high and low molecular weight analytes. The methods and devices of the invention employ labelled reagents which are either analyte analogs or complementary specific binding pair members for the analyte and a novel arrangement of capture zones comprising immobilized specific binding substances for either the analyte or the labelled reagent to effect bound from unbound labelled reagent as a function of analyte concentration. The capture zones are disposed on a non-bibulous matrix defining a flow path from a sample receiving zone to the capture zone. The devices of this invention also include multilane flow paths and multiple capture zones to quantitate analyte.

Abstract: Methods and compositions are disclosed for reducing non-specific binding in a binding assay for the determination of an analyte in a sample where one of the reagents for conducting the binding assay comprises a solid support comprising a polysaccharide. The method comprises including in an assay medium for conducting the binding assay a soluble compound comprising a protein linked to a polysaccharide. Also disclosed are methods and compositions for determining the presence and/or amount of an analyte in a sample suspected of containing the analyte. The methods include as reagents a solid support comprising a polysaccharide and a soluble compound comprising a protein linked to a polysaccharide.

Abstract: The present invention relates to methods of determining anti-infectious agent IgG avidity, for example, human anti-cytomegalovirus and human anti-toxoplasma IgG avidity, using a competitive assay format.

Abstract: Diagnostic devices and methods are provided. The diagnostic devices preferably comprise a test strip with a test area. The sample to be analyzed contacts the test area, which comprises a specific binding partner for the analyte of interest. Analyte, if present in the sample, binds to the immobilized binding partner in the test area and is subsequently contacted with a conjugate. The conjugate specifically binds the analyte and provides a visual indication of the presence of the analyte. The devices may be used for the diagnosis of particular diseases or disorders in a patient, such as HIV or hepatitis. They may also be used to determine if an individual is pregnant.

Abstract: A method and apparatus for the manipulation of colloidal particulates and biomolecules at the interface between an insulating electrode such as silicon oxide and an electrolyte solution. Light-controlled electrokinetic assembly of particles near surfaces relies on the combination of three functional elements: the AC electric field-induced assembly of planar aggregates; the patterning of the electrolyte/silicon oxide/silicon interface to exert spatial control over the assembly process; and the real-time control of the assembly process via external illumination. The present invention provides a set of fundamental operations enabling interactive control over the creation and placement of planar arrays of several types of particles and biomolecules and the manipulation of array shape and size. The present invention enables sample preparation and handling for diagnostic assays and biochemical analysis in an array format, and the functional integration of these operations.

Abstract: An immunoassay comprises the steps of: (a) mixing a whole blood sample with sensitized insoluble carrier particles smaller than erythrocytes to cause an immune agglutination reaction; (b) introducing the resulting immune agglutination reaction mixture including agglutinated particles and unagglutinated particles to a flow cell, irradiating the particles passing through the flow cell with laser light, and detecting scattered lights generated thereby; (c) setting a threshold value for distinguishing unagglutinated particles from agglutinated particles and a threshold value for distinguishing the agglutinated particles from blood cells with regard to intensity of the scattered light; and (d) distinguishing and counting the unagglutinated particles, the agglutinated particles and the blood cells from the scattered lights detected in the step (b), in reference to the threshold values set in the step (c).

Abstract: Novel magnetic assay methods and systems. According to a preferred embodiment, a chromatographic medium is provided that is designed to be contacted with a test solution having activated magnetic particles such that the solution flows bilaterally thereacross. A magnetic field, generated by a magnet or electromagnet, is selectively applied to the medium which causes the charged particles to become substantially bound at a site on the medium specified by the position of the magnet. The assay is multi-configurable and can be modified to isolate target cells and grow cell cultures.

Abstract: A method of single parameter and multiparameter characterizing of cells, particularly immunophenotyping of cells, is provided. The method preferably uses antibody-coated microspheres which are adapted to bind to specific types of cells. One or more sets of coated microspheres are contacted simultaneously or sequentially with a suspension of cells and bind the cells they are adapted to bind to form bead-cell complexes. Cells may bind to one or more microspheres. The bead-cell complexes are then separated from the suspension The complexes are preferably stained and then examined to characterize the cells, preferably the cells bound to the microspheres. A method of quantitating a specific cell type is provided. A kit and apparatus for performing the method are also provided.

Abstract: A method of single parameter and multiparameter characterizing of cells, particularly immunophenotyping of cells, is provided. The method preferably uses antibody coated microspheres which are adapted to bind to specific types of cells. One or more sets of coated microspheres are added simultaneously or sequentially to a suspension of cells and bind the cells they are adapted to bind. Cells may bind to one or more microspheres. The suspension is then filtered to trap bead-cell complexes. The complexes are preferably stained and then examined to characterize the cells, preferably the cells bound to the microspheres. A kit and apparatus for performing the method are also provided.

Abstract: An objective of the invention is to provide a carrier particle latex for an assay reagent capable of assaying a biological sample at a wide range of the concentration in an immunoserological test and capable of being stored stably for a prolonged period, as well as an assay reagent employing the same. The invention is a carrier particle latex for an assay reagent comprising a carrier particle comprising a copolymer of a polymerizable monomer having a phenyl group and a polymerizable monomer having a phenyl group and a sulfonate, wherein said carrier particle has a surface sulfonic acid group amount of 0.005 to 0.7 ?mol/m2 and an average particle size of 0.01 to 1.5 ?m.

Abstract: The present invention concerns a method for producing microparticles loaded with proteins which is characterized in that the microparticles are loaded in suspension under strongly alkaline conditions. The invention also concerns microparticles which can be produced using this method and their use in a binding test e.g. in an immunoassay.

Abstract: A highly sensitive assay is disclosed which combines immunomagnetic enrichment with multiparameter flow cytometric and immunocytochemical analysis to detect, enumerate and characterize carcinoma cells in the blood. The assay can detect one epithelial cell or less in 1 ml of blood and has a greater sensitivity than conventional PCR or immunohistochemistry by 1-2 orders of magnitude. In addition, the assay facilitates the biological characterization and staging of carcinoma cells.

Abstract: A method of detecting an analyte is described in which an up-converting luminescent species that is excited by absorption of long wavelength light is provided as a donor of energy to an acceptor species that can be bound to, or generated in proximity to, the luminescent species. The analyte either alters the proximity between the luminescent species and the acceptor species or alters the absorbance or luminescence properties of the acceptor species. The luminescent energy donor is excited with long wavelength light and transfers up-converted energy to the proximate acceptor species and this transfer of energy is detected by measurement of appropriate luminescence properties of either the donor or of the acceptor or both.

Abstract: It has been found that a urine test for ovarian reserve can be provided which is equivalent in sensitivity to current laboratory methods which determine ovarian reserve based on FSH levels in serum. A lateral flow device for indicating ovarian reserve is disclosed. The device has an application zone for receiving a urine sample, a labelling zone containing label which binds to FSH in the sample, and a detection zone where FSH-bound label is retained. The detection zone has a threshold value which corresponds to a serum FSII level of between 5-20 mIU/ml (e.g. 10 mIU/ml). A test result above the threshold value indicates diminished ovarian reserve.

Abstract: The present invention relates to an in vitro diagnostic method for patients with suspected deep venous thrombosis wherein by combined testing of patients' samples for D-dimer and CRP both the sensitivity and the negative predictive value of DVT diagnostics can be increased up to 100%.

Abstract: A competitive immunoassay, dye and method for rapidly detecting the presence of one or more target ligands within a fluid sample suspected of containing such ligand or ligands. The immunoassay comprises a protein-binding membrane, a first absorbent pad, a second absorbent pad, and a third absorbent pad. The protein-binding membrane has at least two regions of antibodies bound thereto for detecting dissimilar ligands. The second absorbent pad has formed therein a colloidal gold tracer having one, and preferably two or more ligand analog protein complexes adhering thereto. To utilize the system, the immunoassay strip is placed within a fluid sample. To the extent the target ligand is absent, a visual indicator will be provided signaling such absence. To the extent the target ligand is present at or above a threshold level, no such visual signal will be produced.

Abstract: A membrane-based assay device for detecting the presence or quantity of an analyte residing in a test sample is provided. The device utilizes a self-calibrated magnetic binding assay format (e.g., sandwich, competitive, etc.) that includes detection probes capable of generating a detection signal (e.g., fluorescent non-magnetic particles) and calibration probes capable of generating a calibration signal (e.g., fluorescent magnetic particles). The amount of the analyte within the test sample is proportional (e.g., directly or inversely) to the intensity of the detection signal calibrated by the intensity of the calibration signal. It has been discovered that the fluidics-based device of the present invention provides an accurate, inexpensive, and readily controllable method of determining the presence of an analyte in a test sample.

Abstract: The present invention relates to immobilized procainamide analogs, as well as to a method of making immobilized procainamide analogs. These immobilized analogs are prepared by activating the carboxyl group on a substituted p-benzoic acid derivative toward nucleophilic attack; reacting the activated benzoic acid derivative with a polyamine to produce the benzoic acid derivative of Formula 3: and binding the benzoic acid derivative of Formula 3 to a latex polymer having functional groups that react with aliphatic amino groups. A method of conducting an immunoassay using the immobilized procainamide analog Formula 3 is described, comprising the steps of preparing a solution comprising said immobilized procainamide analog; adding a sample suspected of containing procainamide to said solution; adding an anti-procainamide antibody to said solution and observing the rate of increase in solution turbidity following antibody addition.

Abstract: The present invention relates to peptides that are derived from HSV-2 glycoprotein G2 and represent HSV-2 type-specific epitopes. The present invention also provides for compositions comprising these peptides for type-specific serological diagnosis of HSV-2 infection. Methods of using these peptides for type-specific detection of HSV-2 antibodies and differentiation of HSV-2 viral infection from HSV-1 and other herpes family viral infections are further provided.

Abstract: The present invention relates to a systematic process for the creation of functionally organized, spatially patterned assemblies polymer-microparticle composites including the AC electric field-mediated assembly of patterned, self supporting organic (polymeric) films and organic (polymeric)—microparticle composite films of tailored composition and morphology; the present invention further relates to the incorporation of said assemblies into other structures. The present invention. also relates to the application of such functional assemblies in materials science and biology. Additional areas of application include sensors, catalysts, membranes, micro-reactors, smart materials. Miniaturized format for generation of multifunctional thin films.

Abstract: An apparatus for manipulating and testing molecules includes a surface to which the molecule is anchored at multiple points at one end, a paramagnetic bead on which said molecule is anchored at multiple points at its other end, and a magnetic means for applying a force to the bead, said magnetic means being used to control the stretching and rotation of said bead and said molecule. The apparatus also includes an optical magnification means and a camera for the visualization of said bead. The apparatus further includes a computer means to which images from the camera are transmitted. The computer means includes means for analyzing the motions of the bead. The apparatus also includes a rotating means for spinning the magnetic means about an optical axis of the magnification means.

Abstract: Compositions are disclosed comprising (a) a metal chelate wherein the metal is selected from the group consisting of europium, terbium, dysprosium, samarium osmium and ruthenium in at least a hexacoordinated state and (b) a compound having a double bond substituted with two aryl groups, an oxygen atom and an atom selected from the group consisting of oxygen, sulfur and nitrogen wherein one of the aryl groups is electron donating with respect to the other. Such composition is preferably incorporated in a latex particulate material. Methods and kits are also disclosed for determining an analyte in a medium suspected of containing the analyte. The methods and kits employ as one component a composition as described above.

Abstract: A compound linked to a solid support (R) through a divalent linker moiety (X) and which is represented by the following formula: is disclosed. In particular, the 1-hydroxybenzotriazole-6-carboxylic acid is directly linked to the support under mild conditions (i.e., in aqueous or organic solvents at neutral pH and at room temperature). The polymer bound 1-hydroxybenzotriazole-6-carboxylic acid can be used for the derivatization of amines as well as for single step amino group modification of proteins, peptides, and amines via acylation or sulfonylation reactions. A flow through device and method for the single step amino group modifications of proteins, peptides, and amines is disclosed. Also disclosed is a flow through device for the detection of amines in a sample. Additionally, a device and method for the detection of amines in a sample using 1-hydroxybenzotriazole-6-carboxylic acid is disclosed. In a preferred embodiment, the device is used to detect the presence of amines in a spoiled meat product.

Abstract: The present invention is directed to a composition and method for regulating the adhesion of cells and biomolecules to hydrophobic surfaces and hydrophobic coated surfaces. The composition is a biomolecule conjugated end-group activated polymer (EGAP). The biomolecule conjugated EGAP can be put to numerous uses including cell adhesion, cell growth, cell sorting, and other biological assays.

Abstract: The invention relates to the use of specific ligand carriers for detecting prions, and to substances that are capable of binding to prions and that are subsequently used to detect prions.

Abstract: Artificial antibodies or antibody mimics are described. They consist of polymers that carry specific binding sites mimicking the properties of antibodies. There is also described a method for producing artificial antibodies, in which polymerisable monomers carrying functional groups and crosslinking monomers are polymerised in the presence of a print molecule and subsequently the print molecule is removed leaving specific binding sites complementary to the print molecules. There are also described methods for determination and isolation of organic molecules using the artificial antibodies as well as therapeutic and diagnostic methods using these antibodies.

Abstract: This invention relates to a biospecific assay method, in which microparticles coated with the bioaffinity reactant A binding the analyte to be assayed; the sample to be analyzed, and the labelled bioaffinity reactant B are mixed. After the binding reaction the signal strength from the labelled bioaffinity reactant B bound to the microparticles is quantitated for the determination of the concentration of the analyte in the sample. According to the invention, such an amount of sample and microparticles is used in the assay that after binding of the analyte of the sample to the said amount of microparticles, each individual microparticle will emit such a signal strength as to allow the measurement of the analyte concentration over the whole range of typical analyte concentrations, and the signal strength from each microparticle is measured separately.

Abstract: A method for aiding in differentiating irritable bowel syndrome from inflammatory bowel disease by determining the level of total endogenous human lactoferrin in clinical specimens, such as feces, mucus and bile, wherein an elevated level of lactoferrin substantially precludes diagnoses of IBS and other noninflammatory etiologies, and a kit usable in such method are provided. Further provided is a method for quantitating the level of total endogenous human lactoferrin in clinical specimens, such as feces, mucus and bile, to monitor gastrointestinal inflammation in persons having inflammatory bowel disease.

Abstract: A method is provided for the purification of Clostridium difficile Toxin A antigen comprising reacting impure Toxin A with immobilized mono-specific polyclonal antibodies. The polyclonal antibodies are coupled to a hydrazide group containing matrix such as hydrazide activated agarose gel. The immobilized antibody is specific for Toxin A and will greatly purify Toxin A from a Toxin A containing solution. Antibodies raised to Toxin A purified according to the method are of higher activity than antibodies produced from prior art purified Toxin A.

Abstract: A polysaccharide coated carrier having a coating of at least two successive layers of polysaccharide. The first polysaccharide layer spontaneously associates with a second polysaccharide layer and, optionally, the carrier. Each successive layer of polysaccharide spontaneously associates with a preceding layer. Spontaneous association occurs due to the presence of oppositely charged functional groups on each layer of polysaccharide or due to a spontaneous reaction between the functional groups the layers. The carrier may be any surface such as a tube, microtitration plate, bead, particle or the like and is suitable for use in diagnostic or therapeutic methods.

Abstract: A test device and method for determining the presence or absence of one or more analytes in a fluid sample, the test device including a support or member bearing a mark thereon, and a matrix or member containing a capture zone. In operation, an observation area in the test device becomes transparent, thereby allowing the user to view a mark that is present on a support that is disposed beneath the observation area. Typically, the mark on the underlying support is configured as a minus (?) sign. In the absence of analyte in the sample, the test device presents a negative result as a minus (?) signal. In the presence of analyte in the sample, however, the mark operates in concert with a perpendicular test line on the observation area to present a positive result as a plus (+) signal that is visible to the user.

Abstract: Methods and devices for electrochemical detection of a specific binding pair member utilizing a microsphere with an incorporated electroactive marker, wherein a member of the specific binding pair to be detected is bound, directly or through one or more intermediates, to the microsphere. Multiple specific binding pair members may be detected by use of electrochemically distinguishable electroactive markers. Microspheres with incorporated electroactive markers may include one or more functional groups for binding members of specific binding pairs, and are preferably insoluble in aqueous solvents but soluble in selected organic solvents.

Abstract: The present invention provides an agglutination immunoassay, wherein the agglutination of insoluble carrier particles such as latex are stabilized and uniformized to give good reproducibility, and a reagent therefor. In the agglutination immunoassay which comprises allowing an antigenic substance in a sample to bind to insoluble carrier particles carrying substantially neither antigens nor antibodies thereon, and allowing an antibody or an antibody complex which reacts specifically to the antigenic substance to bind to the antigenic substance to give a selective agglutination of the insoluble carrier particles, a homopolymer prepared by polymerization of a monomer such as 2-methacryloyloxyethyl phosphorylcholine having a phosphorylcholine group and a vinyl group, or a copolymer prepared by polymerization of a monomer having a phosphorylcholine group and a vinyl group, with a monomer having a vinyl group such as n-butyl methacrylate is used.