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: 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 improved active electrode for use in planar sensors has been discovered, the electrode prepared by a process comprising combining a base component with a metal paste and heating the paste in the presence of air for a time sufficient to oxidize a portion of the electrode to produce the metal/metal oxide electrode. The electrodes may be incorporated into various planar sensor formats, particularly pH and CO.sub.2 sensors.

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: A luminometer for determining the composition of a specimen sample includes an annular guide path for sample containing cuvettes within a light tight housing. A rotor moves spaced segments through the guide path with the cuvettes positioned between the segments. The luminometer further includes one or two detector assemblies coupled to the housing and positioned to view and detect light emitted by cuvettes as they pass along the guide path between segments. A cuvette is advanced around the housing via the rotor and rotor segments and when the cuvette reaches a predetermined position on the housing, a reagent, such as a base, is added to the cuvette to initiate a chemiluminescent reaction within the cuvette and provide an emission of light energy in a predetermined spectral range. The luminometer has a waste aspiration probe to remove the contents of the cuvette after it passes the detector.

Abstract: An analyzer for performing automated assay testing. The analyzer includes a storage and conveyor system for conveying cuvettes to an incubation or processing conveyor, a storage and selection system for test sample containers, a storage and selection system for reagent containers, sample and reagent aspirating and dispensing probes, a separation system for separating bound from unbound tracer or labeled reagent, a detection system and date collection/processing system. All of the sub-units of the machine are controlled by a central processing unit to coordinate the activity of all of the subunits of the analyzer. The analyzer is specifically suited for performing heterogeneous binding assay protocols, particularly immunoassays.

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: In a system for installing, from a supply of disposable probe tips, one such probe tip on a probe for each sample by an automated fluid analyzer system and for removing the tip after each use to allow a fresh tip to be installed, a mechanism for making a fresh supply of tips available in a carrier tray and for receiving and disposing of empty carrier trays. Multiple probe tip trays, each having a base, a lid, and holding an array of tips are stacked within a chute of the mechanism. A pair of arms are swung up from a substantially vertical position to a horizontal position beneath the chute. An associated latch engages the lid of the lowermost tray within the chute while tray guides, which hold the trays within the chute, separate to release the lowermost tray onto the pair of arms. A delivery rack associated with the analyzer system receives the lowermost tray base from the pair of arms by engaging the tray base with a pair of clips.

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: Disclosed are recombinant, synthetically and otherwise biologically produced novel proteins and polypeptides which are encoded by the DNA sequence for HSV-2 glycoprotein G (gG) or fragments of said gG sequence particularly by the unique sequence for gG or portions of said unique sequence. The unique sequence proteins and polypeptides are serologically active, can be produced easily and safely at low cost, are useful as diagnostic reagents for HSV-2 and as vaccines against HSV-2. Further disclosed are serological assays based on such unique sequence gG proteins and polypeptides that diagnose the presence of herpes simplex virus type 2 (HSV-2) specific antibodies and can differentiate between HSV-2 and herpes simplex virus type 1 (HSV-1) specific antibodies. Such assays are useful to diagnose genital infections, to detect for exposure to HSV-2 and to screen pregnant women to protect newborns from neonatal HSV-2 infection.

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.