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 nethod of verifying sample volume quantifies the fluid volume aspirated and verifies sample uniformity by detecting the presence of foam or clots in the sample. After aspiration, a pressure sensor is used to measure the vacuum needed to hold up the column of fluid in the probe tip. By knowing the geometry of the probe tip, the vacuum can be converted to a sample weight and volume, based on sample densities. Non-ideal conditions, such as foam on the surface of the fluid or a clot in the fluid, result in a sample volume much lighter in the case if foam, or much greater, in the case of a clot, than anticipated. The method also determines the elapsed time of the aspiration. Foamy samples result in aspiration times shorter than normal. Clotted samples result in aspiration times longer than normal.

Abstract: The present invention provides a creatinine sensor material having a first layer of a protonated pH sensitive fluorophore immobilized in a hydrophobic polymer, wherein the fluorophore can react quantitatively with ammonia and the transducing moiety of the fluorophore is neutrally charged when deprotonated; a second layer of creatinine deiminase and a polymer; and a third layer of a polymer. The present invention also provides a method for detecting creatinine using the creatinine sensor material and optical sensing devices that incorporate the creatinine sensor material.

Abstract: The present invention provides a urea sensor material having a first layer of a protonated pH sensitive fluorophore immobilized in a hydrophobic polymer, wherein the fluorophore can react quantitatively with ammonia and the transducing moiety of the fluorophore is neutrally charged when deprotonated; a second layer of urease and a polymer; and a third layer of a polymer. The present invention also provides a method for detecting urea using the urea sensor material and optical sensing devices that incorporate the urea sensor material.

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: 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 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 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.

Abstract: A failsafe apparatus for verifying a volume of aspirated reagent before it is provided to dilute a sample in an automated assay instrument. A pump draws reagent through a tube having a reagent probe disposed at one end. An optical flow detector includes an optical source disposed proximate the tube to illuminate the interior of the tube, and a photodetector oriented ninety degrees about the circumference of the tube from the source to detect reflected illumination from the contents of the tube. The photodetector provides one voltage level with gas/air within the tube, and a second level with a liquid within the tube. A circuit in communication with the detector discriminates between the two levels. The rate at which aspirate is pumped and the volume of the tube from a probe tip inlet to the detector are known constants. Therefore, a given volume of aspirate takes a predictable amount of time to pass from tip to detector.

Abstract: A magnetic conveyor system for transporting test samples in tubes disposed in a sample rack having a magnetic or magnetically attractive region is described. The magnetic conveyor system includes a drive system, a magnet coupled to the drive system and movable in response to the drive system and a tray having a first surface adapted to receive the sample rack. The magnet is spaced a predetermined distance from the first surface of the tray such that the magnet provides a magnetic force at the surface of the tray. The magnetic force engages the magnetically attractive region of the sample rack disposed on the tray to thereby move the sample rack along the first surface of the tray in response to movement of the drive system. When the tray reaches the end of the rack it is moved onto a processing queue tray where it is available for test purposes. A barcode reader reads a bar code on each test sample as it is placed on the process queue to identify one or more tests to perform.

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: A liquid supply module includes one or more sets of bulk liquid containers each supplying a respective reservoir via a liquid supply line. The bulk liquid containers and reservoirs are vented above the highest liquid level in the system. A pump periodically removes a known volume of liquid from a reservoir which is replenished from a bulk liquid container. A sensor detects a liquid/air transition in the liquid supply line to the reservoir indicative of the exhaustion of liquid resupply from the bulk liquid container. Art air vent solenoid valve in communication with the reservoir is closed when an empty bulk liquid container is replaced. Normal pump operation siphons liquid out of the bulk container after container replacement. A control system tracks pump iterations and calculates a number of executable iterations remaining before the reservoir runs dry.