Beckman Instruments, Inc.

Beckman Coulter, Inc.

Julie S Kim

Anthony K Cheng

Chan S Oh

Frank R Shu

Chen-Yie Chien

The invention provides highly sensitive and rapid homogeneous assays which employ particle-enhanced assay formats in concert with capillary electrophoresis and laser-induced fluorescence (LIF) detection to determine the concentration of an analyte of interest in a sample. Such a determination is made by measuring fluorescent signal(s) (i.e., an electropherogram) produced upon LIF of species present in the reaction mixture that are capable of producing such signals. The method of this invention produces simplified electropherograms by reducing the number of signals that must be separated and subsequently measured, and therefore increases the accuracy of the detection and/or quantification of target analyte concentration in a sample.

Particle based homogeneous assays using capillary electrophoresis with laser-induced fluorescence detection

This invention relates to stabilized formulations comprising a glycopeptide antibiotic immobilized on carrier particles, and more particularly stabilized vancomycin bidentate conjugate formulations for assaying the concentration of vancomycin in a test sample. The invention also relates to assay formats that utilize such stabilized formulations. The invention further provides a test kit for detecting the presence of vancomycin in a test sample, wherein the test kit includes a stabilized vancomycin conjugate formulation. The invention further provides a novel rate enhancer for immunoassays for enhancing the rate of binding of an anti-analyte antibody to the analyte.

Homogeneous assay of vancomycin using a stable particle-vancomycin conjugate, a novel rate enhancer, and a novel dose response modulator

An assay for determining the presence of an analyte of interest in a test sample containing an interfering substance that interferes with the assay is disclosed. The assay comprises the steps of forming a reaction mixture by combining in an assay medium (i) an assay system containing components for detecting the analyte of interest, (ii) a test sample containing the analyte and an interfering substance, and (iii) an additional amount of the interfering substance in a quantity sufficient to substantially mask the effect of the interfering substance in the test sample. This reaction mixture is incubated under conditions sufficient to allow complex formation. This resultant complex formation is detected and the presence of the analyte in the test sample is determined.

Method of reducing interferences in assays

Methods for modulating the rates and dose responses of immunoassays through the incorporation of one or more detergents into the immunoassay reaction are disclosed. The methods are particularly suitable for automated immunoassay formats, especially with formats that use analyte-biotin bidentate reagents. The methods may be used to facilitate the detection of any desired, preselected pharmacological agent.

Detergent-facilitated immunoassay for the rapid and quantitative assay

An indirect potentiometric method and diluent for the analysis of lithium are disclosed. The diluent includes effective amounts of a pH buffer and a non-cationic surfactant comprising at least one hydrophobic group, at least one hydrophillic group and being substantially free of polyoxyethylene groups. Most preferably, the pH buffer is tris-(hydroxymethyl) aminomethane-phosphate, and the surfactant is 2, 4, 7, 9-tetramethyl-5-decyn-4,7 diol. An indirect potentiometric determination of lithium in a clinical sample comprises the steps of mixing the sample with a diluent, contacting an aliquot of the diluted sample with a lithium specific ion selective electrode and at least one ion selective elctrode specifically responsive to a monovalent interfering ion, and measuring both the response of the lithium specific ion selective electrode and the monovalent interfering ion specific ion selective electrode, the responses being an indication of the concentration of lithium in the sample.

Indirect potentiometric method and diluent for analysis of lithium

An indirect potentiometric method and diluent for the analysis of lithium are disclosed. The diluent includes effective amounts of a pH buffer, at least one lithium salt, and a non-cationic surfactant containing at least one hydrophobic group, at least one hydrophillic group and being substantially free of polyoxyethylene groups. Most preferably, the pH buffer is tris-(hydroxymethyl)aminomethane-phosphate, the lithium salt is lithium chloride, and the surfactant is 2,4,7,9-tetramethyl-5-decyn-4,7 diol. An indirect potentiometric determination of lithium in a clinical sample comprises the steps of mixing the sample with a diluent, contacting an aliquot of the diluted sample with a lithium specific ion selective electrode and at least one ion selective electrode specifically responsive to a monovalent interfering ion, and measuring both the response of the lithium specific ion selective electrode and the monovalent interfering ion specific ion selective electrode, the responses being an indication of the concentration of lithium in the sample.

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Placentia, CA, United States of America

Julie S Kim