Abstract: A sensor for measuring a concentration of an analyte in a solution. The sensor comprises a substrate layer, an electrode layer and an immobilized enzyme layer. The sensor further includes an enzyme/polymer layer and/or a hydrophobic layer. The enzyme/polymer layer includes an enzyme disposed within a polymer matrix. The hydrophobic layer is formed from a material that is more hydrophobic than the immobilized enzyme layer material. In certain embodiments, the sensor includes the enzyme/polymer layer and the hydrophobic layer disposed between the enzyme/polymer layer and the immobilized enzyme layer such that the enzyme/polymer layer is disposed along the hydrophobic layer within an area above the immobilized enzyme layer.

Abstract: Novel non-competitive assay techniques have been developed which not only improve sensitivity, but also are convenient and less susceptible to interfering factors. They are compatible with existing instruments and can be run in one or more test tubes. The analyte is reacted with labeled specific binder, after which the mixture is reacted with (1) an insoluble material attached to an analyte derivative and (2) a solid phase carrying a binder. The solid phase is then separated, and the label attached to the solid phase is measured. Variations of the procedure include the use of a reversible bridge for attaching the insoluble material to the analyte mimic and the conduct of the assay in various porous media, such as paper, chromatographic and electrophoretic media, and dipsticks.

Abstract: An assay method incorporating at least two different chemiluminescent compounds for detection and/or quantitation of at least two substances in a test sample is described. The synthesis of chemiluminescent reagents or conjugates for use in such methods as well as kits incorporating such reagents are also disclosed. The assays have particular application in the field of clinical diagnostics.

Abstract: An elastomer, especially a fluoropolymeric elastomer, meets requirements necessary for use as a gasket in contact with primary membranes of electrochemical sensors of both blood gas and ionic species in blood. The elastomer can electrochemically seal an electrode of a diced chip (sensor) from a sample chamber, and can electrochemically seal electrodes of neighboring diced chips from each other. Significant simplicity in fabrication of multi-sensor analyzers and stopped-flow method using such analyzers is realized.

Abstract: An electrochemical sensor is designed for use in detecting a concentration of an analyte in a sample solution. The sensor to have a longer useful lifetime, improved stability and improved response time for single or multiple use applications. In one aspect, some of these goals are achieved by providing the multilayer enzyme electrode membrane having both nonporous and microporous layers. The microporous layer is formed from a polymer binder, a polymer powder, a surfactant and a mineral powder. In another aspect, certain of these goals are achieved by the use of a layer comprised of an enzyme disposed within a polymer matrix. In certain embodiments, the multilayer enzyme electrode membrane includes an outermost layer which is capable of dissolving in the sample solution such that the interface between the multilayer enzyme electrode membrane and the sample solution is continually renewed.

Abstract: Diagnostic/prognostic methods are provided for detecting and/or quantitating in the body fluids, preferably serum, of mammals carrying a malignant tumor burden, elevated levels of a portion of the epidermal growth factor receptor (EGFr) which comprises substantially the EGFr ectodomain having a molecular weight in the range of from about 90 kilodaltons (kd) to about 115 kd, preferably from about 95 kd to about 105 kd, and more preferably about 100 kd. Substantially pure compositions comprising EGFr ectodoman protein and/or fragments thereof are disclosed as well as test kits for performing the disclosed assays.

Abstract: A method is provided for detecting or quantitating each of a plurality of substances or at least one substance and an internal reference material or control material in a test sample using at least two different luminescent labelled conjugates. Each luminescent labelled conjugate being characterized in being activated to emit light under different process conditions. The invention also provides for test kits containing at least two different luminescent labelled conjugates for detecting or quantitating presence or absence of at least two substances or at least one substance an internal reference material or control material in a test sample.

Abstract: It has been found that imidazole and related buffers enhance the activity of certain preservatives, for example either (1) a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one or (2) 5-bromo-5-nitro-1,3-dioxane, that are used in clinical diagnostic reagents. It has also been found that these buffers and certain surfactants, such as BRIJ 700 and related hydrophilic surfactants, enhance the precision and accuracy of enzyme biosensors.

Abstract: This invention is directed to novel nucleophilic polysubstituted aryl acridinium conjugates and the methods for preparation thereof. The novel nucleophilic polysubstituted aryl acridinium conjugates are useful in biological assays, including novel assays for the determination of Vitamin B.sub.12, folate, cortisol, estradiol, and thromboxane B.sub.2.

Abstract: Novel acridinium esters that are useful, either alone or when incorporated into liposomes, as chemiluminescent agents in binding assays (e.g., immunoassays and gene probe assays) with improved-sensitivity are disclosed. In addition, the synthesis of these esters and their use in assays for detecting an analyte is described. In particular, assays for testosterone and the Rubella virus are disclosed.

Abstract: Vesicular luminescent conjugates comprising liposomes coupled to molecules with biological activity, such as antigens, antibodies, and nucleic acids, for use in luminescent assays, are described herein. These conjugates encapsulate hydrophilic polysubstituted aryl acridinium esters and are useful as chemiluminescent tracers in immunoassays and other binding assays.

Abstract: A method for diagnosing prostate cancer in a mammal is described. Serum from a mammal is provided. PSA is added to this serum, and the amount of ACT-PSA complex formed is measured. It is determined if the mammal has prostate cancer based on the amount of ACT-PSA complex that is formed. An isolated prostate cancer specific form of ACT which is capable of forming a stable complex with PSA is also described.

Abstract: A sensitive assay method has been discovered that reduces the amount of non-specific binding present in an assay, the method comprising detecting an analyte present in a sample through a specific binding reaction in which either an analogue of the analyte or a specific binding partner of the analyte is immobilized on a solid-phase and said specific binding reaction produces a detectable product immobilized on said solid-phase that may be correlated to the amount of analyte present in the sample wherein said assay employs an effective amount of a surfactant selected from the group consisting of a polyoxyethylene-alkylether, a polyalkylene oxide-modified polydimethylsiloxane block copolymer, a polyalkylene oxide-modified polymethylsiloxane block copolymer, and mixtures thereof to reduce non-specific binding.

Abstract: Provided is a method of preparing dye-based reference materials useful for calibrating or qualifying instrument systems that are diagnostic spectroscopically for hemoglobin and CO-ox fractions. The dye-based reference materials are non-proteinaceous and may be interpreted by CO-oximeter instrument systems as providing a spectrum substantially equivalent to the spectrum of blood, particularly with regard to hemoglobin and hemoglobin CO-ox fractions. Dye-based reference materials may be formulated to provide CO-ox fractions approximating those seen in a clinical setting, including normal physiological CO-ox fractions. The dye-based reference materials may be combined with other ingredients thus making the materials useful as references for pH and blood gas instruments and/or electrolyte instruments in addition to CO-oximeter instrument systems.

Abstract: This invention involved the discovery of novel polymers used as adhesives and a process for their preparation. The polymers were prepared by the nucleophilic substitution, at room temperature, of PVC with substituted alkyltrialkoxysilanes, which can be cured at room temperature to give adhesion of PVC to hydrophilic substrates. These polymers are particularly useful as adhesion promoters in ion-selective electrodes. The invention also involved the application of these adhesive primers to planar electrode substrates to give greatly improved performance in the response of ion-selective electrodes.

Abstract: A novel method for conjugating haptens, ligands or luminescent labels to polynucleotides has been developed. This method involves the formation of a mixed anhydride, followed by reaction of the mixed anhydride intermediate with a nucleophilic group-containing polynucleotide in a DMF/water solvent system. The resulting compound finds usefulness especially in the gene probe area.

Abstract: A reagent pack for keeping fluids with or without suspensions mixed or suspended upon rocking. The reagent pack has at least one chamber divided into separate sub-chambers with a throat region between them defined by baffles for agitation of suspended reagent during rocking of the reagent pack. A continuous lid sealable to the pack has membrane sealed apertures in the lid for allowing access to the underlying chambers and sub-chambers by withdrawal needles. A tray is configured to hold multiple side-by-side reagent packs on respective slides that slide in and out for insertion and withdrawal of the packs. During operation, the tray and associated packs are rocked such as by being periodically inclined with respect to horizontal, providing reagent agitation.

Abstract: A solid shale, multi-use electrochemical sensor having an electrically nonconductive substrate, a working electrode, and a semi-permeable membrane covering the working electrode. The working electrode includes an electrically conductive material adhered to a portion of the substrate. A first portion of the conductive material is covered with an electrically insulating dielectric coating, and a second portion of the conductive material is covered with an active layer. The active layer includes a catalytically active quantity of an enzyme carried by platinized carbon powder particles, which are distributed throughout the active layer. A sensor package for incorporating a sensor is provided.

Abstract: A method for the detection of an analyte in a fluid sample using liposomes encapsulating acridinium esters (lumisomes). Hydrophilic polysubstituted aryl acridinium esters are useful as chemiluminescent markers and can be encapsulated within liposome vesicles without significant leakage of the esters from the vesicles. The lumisomes can be coupled to molecules with biological activity, such as antigens, antibodies, and nucleic acids, and used in luminescent assays.