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 analyze. The analyzer is specifically suited for performing heterogeneous binding assay protocols, particularly immunoassays.

Abstract: A conductivity sensor for measuring hematocrit and a sensor housing for a blood analysis instrument using the conductivity sensor are described. The conductivity sensor includes a seven-electrode conductivity measurement cell in which three symmetric pairs of electrodes are arranged on opposite sides of a central electrode. The central electrode is connected to an AC source and the outermost pair of electrodes, which provide a return path for the current, are maintained at a ground or reference potential. The two inner pairs of electrodes measure the voltage drop along the current flow path. This arrangement confines the measurement current and potential within the sensor chamber, thereby preventing the sensor from interfering with other electrochemical sensors that may be provided in the blood analysis instrument. The sensor housing provides a linear arrangement of flow cells defining a fluid flow path through the housing.

Abstract: New methods are provided for the amplification of a midivariant DNA containing an inserted target specific nucleic acid sequence(s) to enable detection of the presence of a target nucleic acid sequence in a test sample. One method employs midivariant DNA as a template for the synthesis of RNA catalyzed by QB replicase. Two midivariant DNA/probe conjugates including a nonreplicable portion of midivariant DNA and a target specific nucleic acid sequence (probe) are described. An amplification method including the steps of hybridization and ligation of the midivariant DNA/probe conjugates followed by replication of the DNA template has enabled detection of less than 200 template molecules. In a modified amplification method one of the midivariant DNA/probe conjugates further includes a RNA polymerase promoter sequence to enable transcription of the midivariant DNA template into RNA. The sequential ligation-transcription-replication method enables the detection of a single template molecule.

Abstract: A polymeric material which to form a stable, reproducible interface between the ionic and electronic domains of an ion selective sensor, or an ion selective field effect transistor, or the like is provided. When employed in an ion selective sensor, the polymeric material is advantageously provided over a solid internal reference electrode and an ion selective membrane is provided thereover. According to one embodiment, the polymeric material of the invention includes less than about 1.63.times.10.sup.21 immobilized charged sites per gram (less than about 2.72 millaequivalents/gram). According to another embodiment, the polymeric material includes immobilized sites of charge opposite that of mobile ions involved in the redox couple. A preferred polymeric material comprises a copolymer of methacrylamidopropyltrimethylammoniumchloride and methylmethacrylate. In a particularly advantageous embodiment, the ion selective membrane has little or no plasticizer.

Abstract: An improvement to the coated wire electrode has been accomplished via inclusion of a fortiophore into a sensor device. Sensor devices of the present invention include: an internal reference element; a membrane; and a fortiophore. Fortiophores are neutral charge carriers, which complex reversibly a corresponding ion of the conductive material used as the internal reference element. The fortiophore provides an electrochemically defined and reproducible solid internal contact between the membrane and the internal reference element. This solid internal contact, for example, in ion selective sensors, provides more reproducible potential offsets and better precision, and faster wet up. The fortiophores can be utilized in other electrochemical devices.

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: Method and apparatus for enabling resuspension wash and magnetic localization of sample components bound to particles with magnetic properties in reaction vessels during separation and wash for enhanced chemiluminescent signal generation in biomedical assays. The assays involve moving reaction vessels past magnetic arrays that partially localized the particles prior to passing a gap where washing occurs, with or without resuspension, after separating out the unbound components and liquid. The band of particles is further localized by a focusing magnet at the end of the array prior to dosing the vessel with acid for chemiluminescent purposes. A block of soft magnetic material is employed in place of a magnet in the gap to minimize magnetic strength at the gap. Trimmed magnets adjacent the gap cause left, then right, particle shifting that localizes the magnetizable particles. The gap enables improved resuspension by wash, whereas the localized particles enable more efficient resuspension by reagent.

Abstract: Methods and apparatus are provided for non-invasively determining blood pH by a multivariate analysis technique, such as classical least squares (CLS), partial least squares (PLS), or principal components regression (PCR). The technique employs at least one spectral factor based on the difference in the spectrum of a hemoglobin fraction (e.g., oxyhemoglobin) at two different pH's (e.g., pH 7.2 and pH 7.8). The spectral factor is preferably evaluated over the wavelength range of 520-680 nm.

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: A method of inhibiting proteolytic degradation of a thermally-stable intracellular protein is described. The method involves adding 1 or more denaturing agents to a sample which contains the protease and the protein of interest and heating the resulting solution at a temperature and for period of time sufficient to denature the protease. The method optionally includes a step for lysing the cell if the protein of interest is contained in a cell in order to release said protein. Additionally, a method of determining Mx protein induced by interferon in a blood sample is described. The method involves adding to a blood sample a lysing agent, a denaturing agent, and a detergent selected to solubilize Mx protein. The sample containing Mx protein is then heated at a temperature of from about 50.degree. C. to about 60.degree. C. for a period of time of from about 1 minute to about 30 minutes, and the Mx protein in the solution then is determined.

Abstract: Composition, comprising in homogeneous distribution A) at least one salt containing a lipophilic anion, B) a plasticiser-free thermoplastic randomly segmented polyurethane which is soluble in organic solvents, a polyurea or a polyurethane urea, which components are formed from a) 5-45% by weight of an aromatic, cycloaliphatic or linear aliphatic dilsocyanate, b) 0-20% by weight of a linear or branched C2-C12alkylenediol or C2-C12alkylenediamine, c) 0-75% by weight of a polytetrahydrofuran or aminopropyl-terminated polytetrahydrofuran, d) 0-10% by weight of a polyethylene glycol or aminopropyl-terminated polyethylene glycol, e) 0-75% by weight of a polypropylene glycol or aminopropyl-terminated polypropylene glycol, which composition contains f) 15-95% by weight of a hydroxy-, hydroxypropyl- or aminopropyl-terminated polydimethylsiloxane, the percentages relating to the amount of polymer, and the sum of components a) to f) being 100, and C) a nonionic ionophore which forms a complex with Ca++ ions.

Abstract: A polymeric sensing membrane having a Stern-Volmer constant within a pre-determined range of Stern-Volmer constants. The membrane includes a polymeric material having a fluorescent dye molecule dispersed therein. The dye molecule is capable of having its fluorescence collisionally quenched by a gas to be detected by the membrane. In one embodiment, the membrane includes a fluorescent dye molecule which has a relaxation time and a polymeric material having a permeability within a range of permeabilities defined by a mathematical function of the pre-determined range of Stern-Volmer constants. In another embodiment, the membrane includes a polymeric having a permeability and a fluorescent dye molecule having a relaxation time within a range of relaxation times defined by a mathematical function of the pre-determined range of Stern-Volmer constants.

Abstract: A method is provided for more accurately calculating the concentration of analytes or components in test samples. The method includes the use of an algorithm for analysis, and selection of sets of signal measurements from a spectrophotometer. Sets of signal measurements are selected to avoid inhomogeneities, i.e. air bubbles, artifacts and dilution, in test samples being analyzed. The method has application to the spectroscopic determination of the concentration of hemoglobin derivatives or fractions in a blood sample.

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: The present invention comprises methods of determining the performance of an absorbance spectrometer, and, in particular, of CO-oximeters. The methods comprise measuring the absorbance spectrum of a quality control sample and comparing it to a standard spectrum of that quality control. Instrumental error will be the primary factor contributing to the observed difference. The present method also provides techniques for converting the instrumental error manifested in the difference between the measured and standard quality control spectra into blood concentration values comparable to that of real blood. Analysis of test samples on a spectrophotometer; and calibration of the spectrophotometer is also provided.

Abstract: Method and apparatus for transportation and processing of multiple protocol assays within an automated immunoassay analyzer instrument. The apparatus includes a cuvette ring movably coupled to a magnet ring. In one embodiment, the magnet ring and cuvette ring are provided having circular shapes. A temperature controlled housing is disposed about the cuvette and magnet rings to provide a rotary incubation and particle separation chamber. The cuvette ring holds a plurality of cuvettes each of which may have a different assay disposed therein. The cuvette ring advances the cuvettes around the circumference of the incubation chamber. A plurality of discrete processing centers for aspiration and dispensing fluid samples, reagents and wash fluids are disposed at predetermined positions about the incubation chamber.

Abstract: A new method for immobilization of small molecules on solid supports via a macromolecular spacer has been developed. A protein or another macromolecule is first immobilized in an aqueous medium, and the solid support is than washed with an organic solvent. The small molecule is coupled in an organic medium, followed by organic medium washes. The new solid phases are useful for affinity purifications, immunoassays and other binding assays, and for selection of binders by panning procedures.

Abstract: The present invention features stable bulking agents and blocking agents for solid phase materials containing proteins. The proteins have thiol groups which are blocked or chemically inert, preventing the formation of aggregates. Chemical solutions wherein thiol groups, if present, are blocked or chemically inert, are particularly useful in analytical applications and in diagnostic reagents utilizing solid phase materials or particles.

Abstract: A polymeric material which to form a stable, reproducible interface between the ionic and electronic domains of an ion selective sensor, or an ion selective field effect transistor, or the like is provided. When employed in an ion selective sensor, the polymeric material is advantageously provided over a solid internal reference electrode and an ion selective material is provided thereover. According to one embodiment, the polymeric material of the invention includes less than about 1.63.times.10.sup.21 immobilized charged sites per gram (less than about 2.72 millaequivalents/gram). According to another embodiment, the polymeric material includes immobilized sites of charge opposite that of mobile ions involved in the redox couple. A preferred polymeric material comprises a copolymer of methacrylamidopropyltrimethylammoniumchloride and methylmethacrylate.

Abstract: A new method has been developed for conducting a gene probe assay. The preferred technique involves (1) using a gene amplification technique (e.g., PCR) to multiply the gene sequence of interest and (2) using a hybridization--ligation detection methodology, wherein the sequences of probes hybridized to the target sequence allow for separation and detection (e.g., probes might contain a combination of magnetic particles and acridinium esters) to determine if a specific sequence is present.