Abstract: Methods and reagents are disclosed for maintaining the antibody-binding activity of a conjugate of an immunosuppressant drug and a conjugative moiety. The method comprises combining with the conjugate an effective amount of a chelating agent. Compositions include in an aqueous medium (i) a conjugate of an immunosuppressant drug and a conjugative moiety and (ii) a chelating agent in an amount effective to maintain an antibody-binding activity of the conjugate of the immunosuppressant drug and the conjugative moiety. The compositions may be employed in assays for the determination of analytes that include immunosuppressant drug analytes and antibodies for an immunosuppressant drug.

Abstract: Methods and reagents are disclosed for conducting assays. Embodiments of the present methods and reagents are concerned with a solid support such as, for example, a particle. The support includes a chemiluminescent composition that includes a metal chelate. The present inventors observed that, when such support such as, e.g., particles, were employed in assays for the determination of an analyte, stability of signal output by the chemiluminescent composition associated with the particle was unacceptably reduced as compared to particles including other chemiluminescent compositions. In accordance with embodiments of the present invention, the stability of signal output from such particles is enhanced by including in a medium that contains the particles a sufficient amount of one or more stabilizing agents, which may be a chelating agent and/or a metal chelate such as, for example, the metal chelate that is associated with the particle.

Abstract: In some embodiments, the present invention pertains to a method for conjugating a first compound to a second compound wherein the conjugation involves an electrophilic moiety. The method comprises reacting the first compound with the second compound to form a conjugate. The improvement in embodiments of the present invention comprises adding a nucleophilic reagent to the conjugate wherein the nucleophilic reagent forms a neutral product upon reaction with unreacted electrophilic moieties of the conjugate. In some embodiments, the nucleophilic reagent is substantially non-reactive with disulfide bonds in the event that the conjugate comprises disulfide bonds. The conjugate formed is doubly deactivated because the other moiety for linking to the electrophilic moiety is also deactivated.

Abstract: Methods and reagents are disclosed for conducting assays. Embodiments of the present methods and reagents are concerned with a solid support such as, for example, a particle. The support comprises a chemiluminescent composition that comprises a metal chelate. The present inventors observed that, when such support such as, e.g., particles, were employed in assays for the determination of an analyte, stability of signal output by the chemiluminescent composition associated with the particle was unacceptably reduced as compared to particles comprising other chemiluminescent compositions. In accordance with embodiments of the present invention, the stability of signal output from such particles is enhanced by including in a medium comprising the particles a sufficient amount of one or more stabilizing agents, which may be a chelating agent and/or a metal chelate such as, for example, the metal chelate that is associated with the particle.

Abstract: Methods and reagents are disclosed for pretreating a sample suspected of containing a hydrophobic drug for conducting an assay method for detecting the hydrophobic drug. A combination is provided in a medium. The combination comprises (i) the sample, (ii) a releasing agent for releasing the hydrophobic drug and the metabolites from endogenous binding moieties, and (iii) a selective solubility agent that provides for substantially equal solubility of the hydrophobic drug and the metabolites in the medium. The selective solubility agent comprises a water miscible, non-volatile organic solvent and is present in the medium in a concentration sufficient to provide for substantially equal solubility of the hydrophobic drug and the metabolites in the medium. The medium, which may further comprise a hemolytic agent, is incubated under conditions for releasing the hydrophobic drug and the metabolites from endogenous binding moieties.

Abstract: Compositions suitable for use as signal generation components of an immunoassay, and methods for their use. According to one aspect of the invention, the composition includes a carrier having a coating of an aminodextran and a metal chelate incorporated therein. The metal chelate is present in the amount of at least 0.065 ?Mole per gram of carrier, and the aminodextran coating density averaging at least about 45 ?g per milligram of carrier. In another aspect of the invention, carrier is dyed with a complex having the formula: M(L1)x(L2)y, wherein M is a metal selected from the group consisting of europium, terbium, dysprosium, samarium, osmium and ruthenium; L1 is a ligand selected from the group consisting of DPP, TOPO, TPPO; L2 comprises a ligand having the formula wherein R is one or more substituents, each substituent comprising an electron donating group; n=2-10; x=1-2; and y=2-4.

Abstract: Compositions suitable for use as signal generation components of an immunoassay, and methods for their use. According to one aspect of the invention, the composition includes a carrier having a coating of an aminodextran and a metal chelate incorporated therein. The metal chelate is present in the amount of at least 0.065 ?M per milligram of carrier, and the aminodextran coating density averaging at least about 45 ?g per milligram of carrier. In another aspect of the invention, carrier is dyed with a complex having the formula: M(L1)x(L2)y, wherein M is a metal selected from the group consisting of europium, terbium, dysprosium, samarium, osmium and ruthenium; L1 is a ligand selected from the group consisting of DPP, TOPO, TPPO; L2 comprises a ligand having the formula wherein R is one or more substituents, each substituent comprising an electron donating group; n=2-10; x=1-2; and y=2-4.

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: In some embodiments, the present invention pertains to a method for conjugating a first compound to a second compound wherein the conjugation involves an electrophilic moiety. The method comprises reacting the first compound with the second compound to form a conjugate. The improvement in embodiments of the present invention comprises adding a nucleophilic reagent to the conjugate wherein the nucleophilic reagent forms a neutral product upon reaction with unreacted electrophilic moieties of the conjugate. In some embodiments, the nucleophilic reagent is substantially non-reactive with disulfide bonds in the event that the conjugate comprises disulfide bonds. The conjugate formed is doubly deactivated because the other moiety for linking to the electrophilic moiety is also deactivated.

Abstract: In some embodiments, the present invention pertains to a method for conjugating a first compound to a second compound wherein the conjugation involves an electrophilic moiety. The method comprises reacting the first compound with the second compound to form a conjugate. The improvement in embodiments of the present invention comprises adding a nucleophilic reagent to the conjugate wherein the nucleophilic reagent forms a neutral product upon reaction with unreacted electrophilic moieties of the conjugate. In some embodiments, the nucleophilic reagent is substantially non-reactive with disulfide bonds in the event that the conjugate comprises disulfide bonds. The conjugate formed is doubly deactivated because the other moiety for linking to the electrophilic moiety is also deactivated.

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: This invention relates to novel quaternary ammonium immunogenic conjugates and reporter reagents useful for eliciting antibodies and in immunoassays. Processes for preparing such quaternary ammonium immunogenic conjugates and their use in immunoassays and in eliciting antibodies are also disclosed.

Abstract: An agglutination-based method for detecting and/or an analyte by allowing the agglutination reaction between the analyte, a carrier reagent, and an agglutinating agent to occur in the presence of a multivalent ligand.

Abstract: This invention uses the evanescent wave detection of particles to distinguish bound from free in an analyte-binding assay. Illumination below the critical angle is employed, and a beveled window is used to eliminate bulk fluorescence from the emitted evanescent wave liquid. The sample is held in a non-rigid film cuvette.

Abstract: This invention uses the evanescent wave detection of particles to distinguish bound from free in an analyte-binding assay. Illumination below the critical angle is employed, and a beveled window is used to eliminate bulk fluorescence from the emitted evanescent wave liquid. The sample is held in a non-rigid film cuvette.

Abstract: This invention relates to a method for detecting whether contaminants are on or have migrated into the body of a plastic reusable food or beverage container. The invention uses a sensor attached to the inside of the container which changes optical density when it is exposed to certain contaminants. The change in optical density is detected by illuminating the sensor with ultraviolet light and then measuring the effect that the sensor has on the ultraviolet light.

Abstract: Signal to noise ratio of enzyme immunoassays employing peroxidase conjugates can be improved by including polyoxyethylene ether detergent in the assay buffer. Such detergents reduce interference due to blood and also improve sensitivity of assays of blood-free samples.

Abstract: Novel particle reagent for light scattering immunoassays are provided. The particle reagents are high refractive index shell-core polymers, having at least a partial surface coverage by a monomolecular layer of anionic surfactant, covalently bonded to compounds of biological interest. The novel particle reagents are particularly suited to protein immobilization by covalent bonding to the shell and are especially useful for light scattering immunoassays.

Abstract: Novel particle reagents for light scattering immunoassays are provided. The particle reagents are high refractive index shell-core polymers covalently bonded to compounds of biological interest or analogs thereof. A method of measuring unknown concentrations of these compounds of biological interest by measuring changes in turbidity caused by particle agglutination or its inhibition is also provided.

Abstract: Novel particle reagent for light scattering immunoassays are provided. The particle reagents are high refractive index shell-core polymers covalently bonded to compounds of biological interest. A method of measuring unknown concentrations of these compounds of biological interest by measuring changes in turbidity caused by particle agglutination or its inhibition is also provided.