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: Materials and compositions for making triglyceride controls, calibrators and standards are described. The materials are mono- and di- and tri- glycerides of medium length fatty acids mixed into compositions of human serum or other protein solutions to form stable, miscible solutions suitable for use as controls, calibrators and standards in clinical chemistry for measurement and quality control in assays for triglycerides. The materials described have been used as vehicles for oil-soluble, water-insoluble pharmaceuticals and as facial emollient oils for cosmetics, and as such are safe, functional, stable, rancid-resistant and very inexpensive compared with pure materials synthesized or described previously.

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.

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 method for substantially preventing coating of hydrophobic material on a probe of an automated analyzer during an assay is described. An automated analyzer having a probe is provided. A composition comprising a non-denaturing surfactant and a reagent for use in the assay is provided. The probe is contacted with the composition during the assay such that hydrophobic material is substantially prevented from coating the probe on the automated analyzer. Compositions for preventing such probe coating are also described. Methods and compositions comprising a non-denaturing surfactant for enhancing the stability of reagents used in an assay are also described.

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: The assay described herein is predicated on an observation that when acridinium ester labeled tracers are bound to their corresponding binding conjugate immobilized on a metal oxide solid phase, the measurable chemiluminescent light emission of the labeled tracer bound to the solid phase is quenched as compared to the free fraction tracer that is unattached to the solid phase. According to the invention, a non-separation specific binding assay to detect or quantify the presence of an analyte is provided where the entire reaction mixture is flashed (including unreacted tracer) and modulated signal (because of the quench effect) is associated with a reference, thus determining the amount or presence of said analyte in said sample. Disadvantages inherent in heterogeneous assays employing multiple separations may be avoided using this non-separation method.

Abstract: A novel flexible package for an oxygen reference solution has been developed. This package is made from a laminated film including preferably polypropylene as the inner layer, aluminum foil as the middle layer, and polyester as the outer layer. The seams are heat sealed, while an optional access device for allowing access to the solution after the storage period, is attached to the inside wall of the bag without breeching the middle barrier layer.