Abstract: The system for transferring plasma to a test substrate comprises an applicator and the test substrate. The applicator includes a blood reservoir and a filter element which separates cellular components from the blood as plasma is passed to the test substrate. The test substrate includes an absorptive element which receives the plasma from the applicator. In one embodiment, measured amounts of plasma are transferred when the absorptive element becomes saturated, thus stopping the flow of plasma. In another embodiment, excess blood and cellular components are removed from the measured plasma by disengaging the applicator from the test substrate. In another embodiment, plasma transferred to the absorptive element is eluted from the absorptive element by subsequent application of an elution medium.

Abstract: A fluorescent labelling composition comprises a linear polysaccharide backbone molecule having a plurality of target-binding molecules, such as antibodies or nucleic acids, attached at spaced-apart intervals thereon. Each of the target-binding molecules, in turn, includes a multiplicity of fluorescent dye molecules bound thereto. In this way, fluorescent signal introduced to a single target-site on a solid phase surface may be increased without loss of binding activity.

Abstract: A method of assaying bone collagen degradation activity in a human subject. In the method, a human urine sample is reacted with an antibody which (i) is capable of reacting immunospecifically with pyridinium crosslinks selected from the group consisting of native free pyridinoline and native free deoxypyridinoline, and (ii) has a ratio of reactivity toward the selected pyridinium crosslinks and urinary pyridinium peptides larger than 1,000 daltons in molecular weight, of greater than about 5:1. An immunocomplex forms between the antibody reagent and the selected pyridinium crosslinks which are present in the sample, and the amount of immunocomplex is measured. Also disclosed are antibody reagents and kits which can be used in the method.

Abstract: Compounds and methods for detecting the incorporation of a hapten into a protein or macromolecule are disclosed. The compounds comprise haptens bound directly or indirectly to a chromophoric group and a macromolecule-reactive group, whereby incorporation of the hapten into a protein or other macromolecule may be detected.

Abstract: The system for transferring plasma to a test substrate comprises an applicator and the test substrate. The applicator includes a blood reservoir and a filter element which separates cellular components from the blood as plasma is passed to the test substrate. The test substrate includes an absorptive element which receives the plasma from the applicator. In one embodiment, measured amounts of plasma are transferred when the absorptive element becomes saturated, thus stopping the flow of plasma. In another embodiment, excess blood and cellular components are removed from the measured plasma by disengaging the applicator from the test substrate. In another embodiment, plasma transferred to the absorptive element is eluted from the absorptive element by subsequent application of an elution medium.

Abstract: A method of assaying a human urine sample, by measuring a concentration of pyridinium crosslinks from which the concentration of total hydrolysed pyridinoline in the sample can be determined, is disclosed. In the method, a urine sample is reacted with an anti-Pyd antibody reagent which preferably has a ratio of reactivity toward native free pyridinoline and urinary pyridinoline peptides larger than 1,000 daltons in molecular weight, of greater than 10:1. By measuring the extent of immunocomplex formed by the reaction, the concentration of total hydrolysed pyridinoline in the sample can be calculated. Also disclosed are an antibody reagent and kit which can be used in the method.

Abstract: Methods and apparatuses are described for determining the presence of an analyte in a sample suspected of containing the analyte. The method comprises contacting a concentrate of a determinable element capable of being detected by means of a semiconductive electrode with the electrode in the presence of a relatively large volume of an assay medium. The determinable element is present in the concentrate in the amount related to the amount of analyte present in the sample. The volume of the medium in diffusive communication with the concentrate is then reduced and the determinable element is detected by means of the effect that the determinable element has on the semiconductive electrode.

Abstract: Compounds and methods for detecting the incorporation of a hapten into a protein or macromolecules are disclosed. The compounds comprise haptens bound directly or indirectly to a chromophoric group and a macromolecules-reactive group, whereby incorporation of the hapten into a protein or other macromolecules may be detected. The disclosure includes a compound of the formula: ##STR1## wherein n.sub.1 is 1, 2, 3, 4, 5, 6 or 7;n.sub.2 is 0, 1, 2, 3, 4, 5, 6 or 7;R.sub.1 is either a carboxytetramethyl-rhodamyl, sulforhodamyl101, or dinitrophenylaminohexanoyl group; andR.sub.2 is --CO.sub.2 H, --NH.sub.

Abstract: Methods and compositions are provided for assays involving members of a specific binding pair ("sbp members") and members of a signal producing system ("sps members"). The signal producing system is capable of producing a detectible signal in relation to the presence or amount of an analyte in a sample suspected of containing the analyte. Exemplary of sps members are enzymes and enzyme substrates, which react with each other to produce a signal. The improvement of the present invention comprises temporarily delaying the production of the signal without subsequent reagent addition. The delay can be achieved by employing an inhibitor which can be an alternate substrate for the enzyme or a compound which reacts with the product of the enzyme and its substrate in an effective amount.

Abstract: Novel methods and devices are provided for detecting analytes, where the sample is placed upstream from a reagent which is a component of a signal-producing system. The detection zone is provided upstream from the sample, where the amount of reagent which becomes bound at two sites is determined and the two values used for an accurate determination of an analyte.

Abstract: Methods and apparatuses are described for determining the presence of an analyte in a sample suspected of containing the analyte. The method comprises contacting a concentrate of a determinable element capable of being detected by means of a semiconductive electrode with the electrode in the presence of a relatively large volume of an assay medium. The determinable element is present in the concentrate in the amount related to the amount of analyte present in the sample. The volume of the medium in diffusive communication with the concentrate is then reduced and the determinable element is detected by means of the effect that the determinable element has on the semiconductive electrode.

Abstract: Methods and apparatuses are described for determining the presence of an analyte in a sample suspected of containing the analyte. The method comprises contacting a concentrate of a determinable element capable of being detected by means of a semiconductive electrode with the electrode in the presence of a relatively large volume of an assay medium. The determinable element is present in the concentrate in the amount related to the amount of analyte present in the sample. The volume of the medium in diffusive communication with the concentrate is then reduced and the determinable element is detected by means of the effect that the determinable element has on the semiconductive electrode.

Abstract: Methods and compositions are provided for assays involving members of a specific binding pair ("sbp members") and members of a signal producing system ("sps members"). The signal producing system is capable of producing a detectible signal in relation to the presence or amount of an analyte in a sample suspected of containing the analyte. Exemplary of sps members are enzymes and enzyme substrates, which react with each other to produce a signal. The improvement of the present invention comprises temporarily delaying the production of the signal without subsequent reagent addition. The delay can be achieved by employing an inhibitor which can be an alternate substrate for the enzyme or a compound which reacts with the product of the enzyme and its substrate in an effective amount.

Abstract: Method and compositions for performing immunoassays having conjugated fluorescent particles and conjugated catalyst where the particles and catalysts are conjugated to members of a specific binding pair. Bound to the fluorescent particle is a catalyst, usually enzyme, member of a signal producing system, which system includes the fluorescent particle. Another catalyst is bound to a specific binding pair member. The catalyst-specific binding member conjugate becomes bound to the particle, by the intermediacy of the binding of the specific binding pair, producing a quenching product which binds to the particle, resulting in a reduction in fluorescence.

Abstract: Methods and compositions are provided for performing an assay on whole blood samples. The method is for a determination of an analyte which is a member of a specific binding pair (sbp) consisting of ligand and homologous receptor. The method involves a binding agent for the red blood cells in such sample, a solid bibulous element to which is bound at least one sbp member, and a signal-producing system. The method comprises combining the whole blood sample, the binding agent, and none or, where appropriate, one or more members of the signal producing system. The medium is next contacted with a portion of a solid bibulous element to which is bound one of the members of the specific binding pair to allow the medium to traverse such element (immunochromatography). The solid bibulous element is contacted with any remaining members of the signal producing system. Signal resulting from the signal producing system is detected and is related to the amount of the analyte in the sample.

Abstract: Methods and compositions are provided for concentrating particles in a minute area on a solid surface. The method permits the detection of small amounts of analytes by providing for an observable signal in relation to the concentration of particles in the area.

Abstract: Chromatographic immunoassay employing a specific binding pair member and a label conjugate which delineates a border whose distance from one end of the chromatograph relates to the amount of analyte present. By combining the label conjugate and sample in a solution and immunochromatographing the solution, or employing a combination of enzymes, one enzyme being the label and the other enzyme affixed to the chromatographic support, the position of the border defined by the label can be related to the amount of analyte in the sample solution.Preferably, an immunochromatograph is employed having both a specific binding pair member and an enzyme affixed to the support.

Abstract: Methods and compositions are provided for concentrating particles in a minute area on a solid surface. The method permits the detection of small amounts of analytes by providing for an observable signal in relation to the concentration of particles in the area.