Abstract: An assay device and method are provided which allow the determination of the presence or absence of at least one analyte in a test sample, while providing specific identification of the test subject. The assay device includes a reaction medium having at least one reaction zone and at least one control zone, which is capable of providing a pattern suitable for identifying the test subject. The pattern suitable for identifying the test subject is preferably a fingerprint. In a preferred embodiment of the invention, the reaction zone and the control zone include at least one member of a ligand/receptor pair.

Abstract: Separation apparatus and method for separating magnetic and/or magnetically-labeled particles from a test medium. Test medium within a reaction chamber is caused to flow past a collecting surface, and a high-gradient magnetic field is applied to the surface to capture magnetically responsive particles in the test medium. The particles are deflected toward the collection surface by baffles, a spinner, or a sprayer, or are funneled past the surface by a plunger operable to be displaced into close proximity to the surface to provide a narrow flow path for the particle-laden test medium. The particles normally suspended in the medium are separated out of suspension by adhesion to the collection surface. The particles may be resuspended by removal of the surface from the high-gradient field, or removal of the high-gradient field from the surface. The collection surface is a thin-walled non-magnetic material having a plurality of magnetic pole faces positioned therearound.

Abstract: A nucleic acid-bound polypeptide produced by binding a nucleic acid to a polypeptide, a method of producing the nucleic acid-bound polypeptide, and applications of the nucleic acid-bound polypeptide, including immunoassays for an antigen or antibody, such as an agglutination immunoassay are provided.

Abstract: The present invention provides novel microfluidic devices and methods that are useful for performing high-throughput screening assays. In particular, the devices and methods of the invention are useful in screening large numbers of different compounds for their effects on a variety of chemical, and preferably, biochemical systems.

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: By allowing serum or plasma samples collected from humans to react with laminin-1 or a fragment thereof, and then determining whether or not anti-laminin-1 antibody, an auto-antibody against laminin-1, in the sample bound to laminin-1 to detect anti-laminin-1 antibody in the sample, gynecology-related diseases such as habitual abortion, sterility, infertility, and endometriosis can be diagnosed.

Abstract: The present invention relates to the use of fluorogenic or chromogenic dyes as reporter molecules for detecting cell entry by a specific molecule.

Abstract: Methods, compositions and kits are disclosed. The compositions are light emitting and comprise a polymeric matrix having dissolved therein a photoactive compound. The composition has the characteristic that, after activation of the photoactive compound, the rate of decrease in the intensity of light emission at any time during a 20-fold decrease in the intensity is proportional to the intensity of the light emission. In one embodiment the polymeric matrix is comprised of particles of about 20 nm to about 100 ?m in diameter to which is bound a specific binding pair member. The particles generally comprise a polymeric matrix having dissolved therein about 1 to about 20% by weight of a dopant. The compositions may be used in methods for determining an analyte. A combination is provided comprising (1) a medium suspected of containing the analyte, (2) and the aforementioned composition. The photoactive substance is activated and the effect of the activating on the optical properties of the combination is detected.

Abstract: Disclosed are devices for detecting the presence of a preselected analyte in a fluid sample. The devices comprise a substrate microfabricated to define a sample inlet port, and a mesoscale flow system that includes a sample flow channel extending from the inlet port. The mesoscale flow system further includes an analyte detection region in fluid communication with the flow channel comprised of a binding moiety for specifically binding the analyte. The detection region is constructed with a mesoscale dimension sufficiently small to enhance binding of the binding moiety and the analyte. The binding moiety may be immobilized in the detection region. The mesoscale detection systems of the invention may be used in a wide range of applications, including the detection of cells or macromolecules, or for monitoring reactions or cell culture growth.

Abstract: The present invention relates to determining the prethrombotic state, in particular determining an amount or presence of circulating microparticles and/or stimulated procoagulant cells.

Abstract: Disclosed are devices for detecting the presence of a preselected analyte in a fluid sample. The devices comprise a substrate microfabricated to define a sample inlet port, and a mesoscale flow system that includes a sample flow channel extending from the inlet port. The mesoscale flow system further includes an analyte detection region in fluid communication with the flow channel comprised of a binding moiety for specifically binding the analyte. The detection region is constructed with a mesoscale dimension sufficiently small to enhance binding of the binding moiety and the analyte. The binding moiety may be immobilized in the detection region. The mesoscale detection systems of the invention may be used in a wide range of applications, including the detection of cells or macromolecules, or for monitoring reactions or cell culture growth.

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: A hand held, self-contained, automatic, low power and rapid sensor platform for detecting and quantifying a plurality of analytes. A sample solution potentially containing an unknown amount of an analyte is passed through an affinity column which contains antibodies to which the analyte binds thereby extracting the analyte. The affinity column is then rinsed to remove any other chemicals that may fluoresce. The rinsed affinity column is then eluted with a known volume of elution fluid causing the analyte to release from the antibody and dissolve in the fluid (eluant). The eluant is then placed in the quartz cuvette of a fluorometer. The analyte suspended in the eluant fluoresces at a waveband which is different than that of the light source that excites it. The amount of fluorescence is measured and the level of analyte determined.

Abstract: Heterogeneous assays for different analytes in a single biological sample are performed simultaneously in a multiplexed assay that combines flow cytometry with the use of magnetic particles as the solid phase and yields an individual result for each analyte. The particles are distinguishable from each other by characteristics that permit them to be differentiated into groups, each group carrying an assay reagent bonded to the particle surface that is distinct from the assay reagents of particles in other groups. The magnetic particles facilitate separation of the solid and liquid phases, permitting the assays to be performed by automated equipment. Assays are also disclosed for the simultaneous detection of antibodies of different classes and a common antigen specificity or of a common class and different antigen specificities.

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 elektrokinetic 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: Immunoassay methods and apparatus are provided which utilize flow cytometry, coated latex microspheres, and fluorochrome labeled antibodies, to simultaneously detect the presence and amount of one or more analytes in a sample. Beads of several different sizes, colors or shapes, each bead are coated with a different analyte, for the simultaneous detection of one or more analytes and of cell components. The invention is also directed to platelet Ig positive control reagents and assays which provide for the setting of the fluorescence positive region for each patient. The platelet control is sized to fit between the platelets and red cells and thus making it ideal as a true biological control.

Abstract: The present invention provides a system for the improved detection of ecstasy-class compounds in biological samples. New ecstasy-class analogs are provided for detection of such ecstasy-class drugs. These analogs are compounds, or salts thereof, of a 2-amino-methylenedioxyphenyl (MDP) derivative attached to Z, where Z is a moiety capable of bonding, either directly or indirectly, with an immunogenic carrier, a detectable label, or a solid capture vehicle. Such analogs may be used to construct immunogens, enzyme or enzyme-donor conjugates, and other conjugates. The immunogens reproducibly generate antibodies with an exquisite ability to distinguish various ecstasy-class drugs in biological samples from potentially interfering substances. The specific antibodies and the conjugates may be used to distinguish and measure various ecstasy-class compounds in biological samples, such as those obtained from an individual suspected of substance abuse.

Abstract: The invention relates to a method of evaluating the immunological status of a subject comprising the steps of 1) determining the content of an antibody in a liquid sample from the subject using an immunoassay, wherein the reaction between the antibody of the sample and a ligand in the form of an antigen, an antibody or a hapten, the ligand being directed to the Fab region of the sample antibody, is carried out in the presence of other constituents of the sample to obtain a measurement 1, 2) determining the content of an antibody in the liquid sample using an immunoassay, wherein the reaction between the antibody of the sample and a ligand in the form of an antigen, an antibody or a hapten, the ligand being directed to the Fab region of the sample antibody, is carried out in the absence of other constituents of the sample to obtain a measurement 2, and 3) interrelating measurements 1 and 2 to express the interference and using the interference as a parameter for evaluating the immunological status of the subje

Abstract: Encoded combinatorial chemistry is provided, where sequential synthetic schemes are recorded using organic molecules, which define choice of reactant, and stage, as the same or different bit of information. Various products can be produced in the multi-stage synthesis, such as oligomers and synthetic non-repetitive organic molecules. Conveniently, nested families of compounds can be employed as identifiers, where number and/or position of a substituent define the choice. Alternatively, detectable functionalities may be employed, such as radioisotopes, fluorescers, halogens, and the like, where presence and ratios of two different groups can be used to define stage or choice. Particularly, pluralities of identifiers may be used to provide a binary or higher code, so as to define a plurality of choices with only a few detachable tags. The particles may be screened for a characteristic of interest, particularly binding affinity, where the products may be detachable from the particle or retained on the particle.

Abstract: Immunoassay methods and apparatus are provided which utilize flow cytometry, coated latex microspheres, and fluorochrome labeled antibodies, to simultaneously detect the presence and amount of one or more analytes in a sample. By combining FALS and fluorescence, it is practical to use beads of several different sizes, colors or shapes, each bead coated with a different analyte, for the simultaneous detection of one or more analytes and of cell components such as platelets in a sample.

Abstract: The present invention relates to an interactive system comprising 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). That interactive system is suitable for presenting and eliminating substances in liquids.

Abstract: A particle-enhanced assay for determining an analyte in a test sample in which an additive for reducing non-specific particle aggregation is added in an amount to substantially reduce non-specific aggregation. The additive is selected form the group consisting of triethanolamine, trimethanolamine, N-butyldiethanolamine, 3-dimethylamino-2-methylpropyl chloride, N,N-dimethylglycine, N,N-dimethylguanidine, N,N-dimethylglycine ethyl ester, 3-dimethylaminopropionitrile, and N,N-dietylacetamide.

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: A method for judging an autoimmune disease by detecting the existence of an anti-Reg protein autoantibody in a specimen; and a method for judging insulin-dependent or non-insulin-dependent diabetes mellitus. A method for detecting an anti-Reg protein autoantibody by bringing into a specimen into contact with an antigen component and detecting the formation of an immune complex. A reagent for diagnosing autoimmune disease which contain an antigen component capable of binding specifically to the anti-Reg protein autoantibody; and a reagent for diagnosing insulin-dependent or non-insulin-dependent diabetes mellitus.

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: This invention provides a novel fluorescent particle including a core or carrier particle having on its surface a plurality of smaller polymeric particles or nanoparticles, which are stained with different fluorescent dyes. When excited by a light source they are capable of giving off multiple fluorescent emissions simultaneously, which is useful for multiplexed analysis of a plurality of analytes in a sample. The coupled complex particles carrying on their surface fluorescent nanoparticles, methods of preparing such polymer particles, and various applications and methods of using such particles are claimed.

Abstract: This invention relates to preservative solutions for peptides, for example, parathyroid hormone, insulin-like growth factor binding protein 3 (IGFBP3), adrenocorticotropic hormone (ACTH) and mixtures thereof. Preferably, the peptides preserved by the solutions are non-reconstituted. In one embodiment, the preservative solutions comprise a polyvinyl alcohol, EDTA component and molybdic component.

Abstract: This invention provides a simple and convenient, single stage, single vessel cell extraction and assay method which is suitable for the extraction and measurement of a range of different types of analyte which occur as cellular components. The invention also provides kits of reagents suitable for performing cellular extraction and measurement as a single stage, single vessel process.

Abstract: The invention relates to a method for detecting specific target-cells in a simple and time saving way, using paramagnetic particles, antibodies recognizing the Fc portions of target-cell associating antibodies and target-cell associating antibodies directed to specific antigen determinants in the target-cell membranes. Incubation of the cell suspension with a mild detergent and/or second set of antibodies or antibody fragments, prelabeled or not with fluorescent agents, metallocolloids, radioisotopes, biotincomplexes or certain enzymes allowing visualization, with dramatically increase the specificity of the method. The method can further be used for isolation of the target-cells by magnetic field application and kit for performing the method according to the invention is described.

Abstract: The present invention provides an immunoassay for specifically measuring with high sensitivity PIVKA-II in serum or plasma through antigen-antibody reaction by adding an animal serum containing thrombin and/or an antibody reacting with human fibrin-like related substances to the reagents. The immunoassay of the invention comprises the steps of adding thrombin and/or an antibody reacting with human fibrin-like related substances to the reagents, and measuring PIVKA-II in serum or plasma.

Abstract: The present invention relates to equine Fc epsilon receptor alpha chain nucleic acid molecules, proteins encoded by such nucleic acid molecules, antibodies raised against such proteins, and inhibitors of such proteins. The present invention also includes methods to detect IgE using such proteins and antibodies. Also included in the present invention are therapeutic compositions comprising such proteins, nucleic acid molecules, antibodies and/or inhibitory compounds as well as the use of such therapeutic compositions to mediate Fc epsilon receptor-mediated biological responses.

Abstract: A method for the detection of an analyte of interest in a sample, which method comprises the steps of: (1) forming a composition comprising (a) a sample, (b) at least one substance selected from the group consisting of (i) added analyte of interest or an analog of the analyte of interest, (ii) a binding partner of the analyte of interest or its said analog, and (iii) a reactive component capable of binding with (i) or (ii), wherein one of said substances is linked to a label compound having a chemical moiety capable of being induced to luminesce, and (c) a plurality of particles capable of specifically binding with the analyte and/or a substance defined in (b) (i), (b) (ii), or (b) (iii); (2) inducing the label compound to luminesce; and (3) measuring luminescence emitted by the composition to determine the presence of the analyte of interest in the sample.

Abstract: A ferromagnetic thin-film based magnetic field detection system used for detecting the presence of selected molecular species. A magnetic field sensor supported on a substrate has a binding molecule layer positioned on a side thereof capable of selectively binding to the selected molecular species. The magnetic field sensor can be substantially covered by an electrical insulating layer having a recess therein adjacent to the sensor in which the binding molecule layer is provided. An electrical interconnection conductor can be supported on the substrate at least in part between the sensor and the substrate, and is electrically connected to the sensor. The magnetic field sensor can be provided in a bridge circuit, and can be formed by a number of interconnected individual sensors. A polymeric channel and reservoir structure base is provided for the system.

Abstract: Heterogeneous assays for different analytes in a single biological sample are performed simultaneously in a multiplexed assay that combines flow cytometry with the use of magnetic particles as the solid phase and yields an individual result for each analyte. The particles are distinguishable from each other by characteristics that permit them to be differentiated into groups, each group carrying an assay reagent bonded to the particle surface that is distinct from the assay reagents of particles in other groups. The magnetic particles facilitate separation of the solid and liquid phases, permitting the assays to be performed by automated equipment. Assays are also disclosed for the simultaneous detection of antibodies of different classes and a common antigen specificity or of a common class and different antigen specificities.

Abstract: An agglutination assay method for quantitatively determination of an analyte in a liquid sample using particles bearing an anti-analyte. A non-fluid substance which retains the particles while suppressing the diffusion of the particles therein is used as a medium which is to be a place where the agglutination of the particles takes place. Upon analysis, a solation agent is added to the non-fluid substance medium to increase the fluidity of the non-fluid substance, thereby the particles bearing the anti-analyte can diffuse in the medium to cause the agglutination with the analyte. Preferably, the solation agent is added to the non-fluid medium together with the sample. The non-fluid substance medium containing the particle-labeled anti-analyte can be stored with a higher stability in the dry state. A dry analysis element for enabling such analysis method is also provided.

Abstract: A waveguide probe for the detection of pathogens in a sample which comprises a laser, a first and a second tubes that converge at a point to form a proximal end. A magnet is positioned in the end to configure to focus paramagnetic microspheres attached to antigen/antibody/optically labeled antibody complexes in the field of view. The proximal end is polished to form an aperture.

Abstract: An immunoassay for detecting an antigen in a sample, by: (a) sequentially contacting the sample with (i) a first antibody which is capable of specifically binding to a first binding site on the antigen, and then (ii) a second antibody which is capable of specifically binding to a second binding site on the antigen, thereby forming, when the antigen is present in the sample, an agglutinate comprising the first antibody, the antigen, and the second antibody; followed by (b) optically measuring the amount of the agglutinate.

Abstract: An analytical test device useful for example in pregnancy testing, comprises a hollow casing (500) constructed of moisture-impervious solid material, such as; plastics materials, containing a dry porous carrier (510) which communicates indirectly with the exterior of the casing via a bibulous sample receiving member (506) which protrudes from the casing such that a liquid test sample can be applied to the receiving member and permeate therefrom to the porous carrier, the carrier containing in a first zone a labelled specific binding reagent is freely mobile within the porous carrier when in the moist state, and in a second zone spatially distinct from the first zone unlabelled specific binding reagent for the same analyte which unlabelled reagent is permanently immobilised on the carrier material and is therefore not mobile in the moist state, the two zones being arranged such that liquid sample applied to the porous carrier can permeate via the first zone into the second zone, and the device incorporating me

Abstract: Use of pregnancy-associated plasma protein-A as a marker for inflammatory conditions, and in particular, for acute coronary syndromes is described.

Abstract: The invention is directed to synthetic receptor(s) which comprises a polyfunctional organic template covalently linked to two or more oligomers which may independently be the same or different and may independently be straight chain, cyclic or branched. The template may be linked to an identifier which uniquely defines the synthetic receptor. The identifier is a stable chemical molecule or a plurality of stable chemical molecules distinguishable and detectable to picomolar levels or may be an oligonucleotide. In a preferred embodiment, the template is covalently linked to a solid support which is linked to an identifier. In addition, the invention includes methods of preparing synthetic receptors and synthetic receptor libraries. The synthetic library may be linked with identifiers such that the library comprises a plurality of different synthetic receptor members.

Abstract: Methods for detecting anti-lipidic particles antibodies and lipidic particles in cellular membranes for the diagnosis of diseases associated to the antiphospholipid syndrome are disclosed. Kits or sets to put these methods of diagnosis into practice are also disclosed. Methods for the therapeutically treatment of diseases associated to the antiphospholipid syndrome are disclosed as well. In addition, methods for the detection of the diverse physiologic states of cells, and those kits useful for this are also disclosed.

Abstract: An ultrasonic energy source is used to provide a variable force for measuring the binding forces between molecular entities and for sensing the presence of an analyte in a test sample. The device includes a surface that has a first binding member attached thereto and one or more particles that have a second binding member attached thereto. A reaction vessel is provided for exposing the surface to the particles whereby, if the first binding member has a binding affinity for the second binding member, a complex is formed between individual first binding members and individual second binding members and the particles thereby become immobilized with respect to the surface. The ultrasonic energy source is positioned for applying a variable ultrasonic force onto the surface, and the position of the particles is monitored as the intensity of the ultrasonic force is varied.

Abstract: It has been found that casein and salts of casein are useful as replacements for, or in addition to, BSA as materials for coating solid phases, particularly magnetic particles, used for immunoassays and other binding assays for separation of the desired analyte. By using casein, immunoassays having improved stability and few discordant samples have been developed. Casein used at a concentration of 0.05-4.0 grams per gram of paramagnetic particle (optimally approximately 0.78-1.2 grams of casein per gram of magnetic particle) has been found to confer this benefit. In addition, a process for coating solid phases has been invented, said process comprising the mixing of casein with magnetic particles at 30-60° C. for 5-180 hours, said process resulting in casein-coated paramagnetic particles which either (1) already have combined therewith active ingredients needed in the binding assay or (2) are capable of reacting with active ingredients needed in the binding assay.

Abstract: A process for detecting an analyte which process comprises (a) contacting a sample suspected of containing said analyte with a containment means comprising a barrier which separates signal generating reagents from said sample, in the presence of an element which interacts specifically with said analyte, under conditions whereby interaction between the analyte and the said element results in activation of the signal generating reagents within the containment means on the side of the barrier opposite to the sample, and (b) detecting any signal generated and retained within the containment means from the sample side of the barrier. The process of the invention provides for sensitive detection of very small numbers of analyte materials using measurement techniques which include counting methods such as flow cytometry.

Abstract: A method for counting leukocytes which comprises liberating elastase from granulocytes contained in a specimen, adding an anti-granulocyte elastase antibody to the thus liberated elastase, measuring the antibody bonded to the elastase to thereby determine the concentration of the elastase, and then calculating therefrom the number of leukocytes contained in the specimen with the use of the ratio of the leukocyte count to the elastase concentration. This method makes it possible to conveniently and less expensively count leukocytes at a high accuracy comparable to the one established by using a conventional automatic blood cell counter, as the figure shows.

Abstract: A method for assaying an analyte in a sample. The method comprising the steps of a) contacting the sample with material comprising a receptor which is present in a liposome and which liposome comprises a detectable functionality, said contact occurring under conditions resulting in binding of the receptor to analyte if present before or concomitant with step b, wherein step b) consists of contacting the sample with an immobilised ligand for the receptor said contact occurring under conditions resulting in binding of the receptor to the ligand, with steps a and b being followed by c) separating the resulting immobilised ligand-receptor fraction and the receptor fraction present in solution and d) assaying the detectable functionality of the receptor in a fraction from step c) in a manner known per se for its detection.

Abstract: The invention relates to an immunoassay apparatus, comprising a dry, porous substrate having at least two sections (1, 2), communicating with one another in the moist state by capillary action, wherein the first section (1) has a marked detection reagent for the substance to be detected and the second section (2) has an immobilized binder reagent for the substance to be detected, and wherein the reaction product comprising the substance to be detected and the marked detection reagent migrates by capillary action from the first section into the second section in the moist state, and is characterized in that the marked detection reagent is a dye-carrying reagent for nicotine or cotinine.

Abstract: The invention relates to a new dipstick assay for detecting and quantifying the content of an target analyte in a sample. The assay is particularly useful for example in the diagnosis and monitoring of alcoholism by the detection of asialo transferrin or carbohydrate free transferrin (CFT). Thus, provided is a dipstick for determining the content of a target analyte variant in a mixture of analyte variants in a sample, comprising: a) a sample application zone, b) a screening zone having an immobilised binding ligand having a binding affinity for a non-target analyte variant or varinats, c) a conjugate zone comprising a detector reagent, d) a reading zone for detection of said analyte.

Abstract: Methods, compositions and kits are disclosed. The compositions are light emitting and comprise a polymeric matrix having dissolved therein a photoactive compound. The composition has the characteristic that, after activation of the photoactive compound, the rate of decrease in the intensity of light emission at any time during a 20-fold decrease in the intensity is proportional to the intensity of the light emission. In one embodiment the polymeric matrix is comprised of particles of about 20 nm to about 100 &mgr;m in diameter to which is bound a specific binding pair member. The particles generally comprise a polymeric matrix having dissolved therein about 1 to about 20% by weight of a dopant. The compositions may be used in methods for determining an analyte. A combination is provided comprising (1) a medium suspected of containing the analyte, (2) and the aforementioned composition.

Abstract: The present invention relates to the substantial elimination of errors attributable to carryover microspheres, doublets, or misclassification of microsphere subsets. The present invention is based upon passing a sufficient minimum number microspheres through the flow analyzer during an assay run.