Abstract: The present disclosure provides among other things immunoassays exhibiting reduced cross-reactivity with analyte metabolites. Additionally, the present disclosure provides diagnostic immunoassays to determine the concentration or level in a test sample of a hydrophobic drug that metabolizes in vivo or in vitro to form cross-reacting metabolites wherein cross-reactivity with such metabolites of the drug analyte is reduced. In particular, the disclosure provides such immunoassays where the hydrophobic drug is an immunosuppressant drug such as cyclosporine A.

Abstract: The present disclosure provides among other things immunoassays exhibiting reduced cross-reactivity with analyte metabolites. Additionally, the present disclosure provides diagnostic immunoassays to determine the concentration or level in a test sample of a hydrophobic drug that metabolizes in vivo or in vitro to form cross-reacting metabolites wherein cross-reactivity with such metabolites of the drug analyte is reduced. In particular, the disclosure provides such immunoassays where the hydrophobic drug is an immunosuppressant drug such as cyclosporine A.

Abstract: Methods and kits for measurement of concentration of FK778 in a biological sample by means of an immunoassay, preferably a competitive immunoassay. In one aspect, the method and kit involve the use of (a) an antibody to FK778 conjugated to a label, e.g., an acridinium label, (b) an antibody to FK778 not conjugated to a label, (c) a solid phase containing an antibody to a first hapten, e.g., a fluorescein hapten, and (d) a bihapten comprising a first hapten and FK778 or an analogue of FK778, e.g., a bihapten comprising a fluorescein hapten and a FK778 hapten. In another aspect, the method and kit involve the use of (a) antibody to FK778, (b) a bihapten comprising FK778 or an analogue of FK778 and a first hapten, e.g., a bihapten comprising the fluorescein hapten and the hapten of FK778 or an analogue of FK778, and (c) a pretreatment reagent.

Abstract: Provided are microparticle forms of carbon, carbon catalysts and carbon-containing electrically conductive materials which are covalently linked to peroxidase. The carbon:peroxidase conjugates are suitable for use as substrates in conventional electrodes. Surprisingly, the conjugates display very little sensitivity to known interfering substances and thus are suitable for use as interference free electrodes.

Abstract: Provided are microparticle forms of carbon, carbon catalysts and carbon-containing electrically conductive materials which are covalently linked to peroxidase. The carbon:peroxidase conjugates are suitable for use as substrates in conventional electrodes. Surprisingly, the conjugates display very little sensitivity to known interfering substances and thus are suitable for use as interference free electrodes.

Abstract: The present invention provides an immobilization medium which can immobilize bioreagents to support materials and which dries to a water resistant layer or film. The immobilization medium comprises (i) a liquid or fluid binding reagent and (ii) complexes of a bioreagent immobilized to a solid phase which are evenly dispersed within the binding reagent. The suspension can further include supplemental ingredients evenly dispersed throughout the medium which can provide the medium with electrochemical properties, enhance the stability of the immobilized bioreagent and/or improve the medium's capability of drying to a substantially water resistant or insoluble layer. The immobilization medium provided by the instant invention is in the form of a homogeneous liquid suspension.

Abstract: This invention encompasses a method for measuring unsaturated thyroxine binding protein sites in a sample comprising intermixing with the sample an effective amount of fluorescent labeled tracer having binding affinity for thyroxine binding proteins and then measuring the amount of tracer bound to the thyroxine binding protein using fluorescence polarization techniques.