Abstract: This invention provides methods of improving assays for the quantitation of a protein in a sample by enhancing equimolar detection of the protein. Detection is enhanced by modifying the reaction environment of the protein. This invention further provides improved reagent particles for use in the detection and/or quantitation of an analyte in a sample, where the reagent particles comprise two or more coatings of the same or a different substance, such as an antibody, immobilized on an insoluble particle. This invention further provides a method of increasing the sensitivity of particle-enhanced immunoassays by increasing the size of the aggregates that are formed in the assay. Aggregate size is increased by combining the sample with three different antibodies: an analyte-specific antibody immobilized on an insoluble particle, a second antibody specific analyte, and a linker antibody which specifically binds the second antibody but does not bind to the analyte.

Abstract: Bidentate reagents for rapidly and quantitatively assaying the concentration of pharmacological agents in biological samples are described. The reagents are used in an immunoassay format for determining the concentration of desired, preselected pharmacological agents, such as benzoylecgonine, cocaine, an opiate, PCP, digoxigenin, acetaminophen, carbamazepine, phenytoin, primidone, theophylline, an aminoglycoside antibiotic, vancomycin, quinidine or a cannabinoid.

Abstract: An assay for detecting the presence or amount of a target polynucleotide sequence of interest in a test sample is disclosed. The assay comprises the steps of forming a reaction mixture by combining in an assay medium (i) a first reagent and (ii) an aliquot of the test sample suspected of containing the target polynucleotide sequence. The reaction mixture is subjected to denaturing conditions, and exposed to hybridization conditions allowing the first reagent to hybridize with any target polynucleotide present. A second reagent is then added, the reaction mixture undergoes hybridization conditions and the change in turbidity of the reaction mixture is detected, correlating with the presence of the target polynucleotide in the sample.

Abstract: A sensor comprising a sensing element capable of sensing a component in an aqueous medium and an overcoating at least partially covering the sensing element. The overcoating comprises a water insoluble, component permeable, cross-linked cellulosic material and an effective amount of an opaque agent.

Abstract: An apparatus for measuring the concentration of a component in a medium comprising:an optical sensor including at least one optical indicator for providing an optical signal which varies in response to the presence of a component in a medium;an optical signal fiber capable of transmitting the optical signal from the optical sensor; anda supply reservoir associated with the optical sensor and acting to provide additional optical indicator to the optical sensor.

Abstract: A sensor comprising a sensing element capable of sensing a component in an aqueous medium and an overcoating at least partially covering the sensing element. The overcoating comprises a water insoluble, component permeable, cross-linked cellulosic material and an effective amount of an opaque agent.

Abstract: An optical sensor which is a gas permeable silicone polymeric matrix having at least one optical indicator therein for providing an optical signal in response to excitation light. The optical indicator essentially comprises a mixture of non-polar derivatives of a polynuclear aromatic compound.