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: This invention relates to magnetic particles comprising mixed oxides of divalent metals and iron (III), having a diameter of 1-10 nm and a surface area of 120-350 m.sup.2 /g, with silanes bound to the surface of said particle. It also relates to (1) the process for making said particles by simultaneous precipitation and silanization from aqueous solution and (2) their use as carrier materials for the magnetic separation of substances immobilized therewith.

Abstract: A system for electrochemical measurement of glucose concentration in an undiluted test sample, e.g. blood is provided containing a sensor including a three-layered contiguous membrane. The membrane has a thickness of 50 to 130 microns, and is composed of a 1 to 10 micron thick first layer, a 10 to 30 micron thick second layer having an average pore diameter of 15 nanometers and a 40 to 80 micron thick third layer containing glucose oxidase. The third layer is less dense than the first and second layers and the first layer is more dense than the second layer. The layers of the membrane are fused together such that no clear distinction can be made between the layers at the boundary. The sensor is calibrated in a standard glucose solution which includes catalase as a hydrogen peroxide scavenger, and the sensor has a response that is linear throughout the concentration range of glucose in an undiluted sample.

Abstract: Methods and test kits for detecting, or detecting and quantitating functional nuclear receptors in cell or tissue samples are disclosed. Such methods provide highly sensitive assays requiring small sample sizes and short turnaround times. The methods are useful in developing prognoses and/or treatment programs for cancer patients, especially in determining whether therapy to interfere with the receptor's activation of gene transcription, such as, endocrine therapy, would be helpful.

Abstract: A solid state, 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 novel process for the use of antisense oligonucleotides and analogs thereof has been developed. Namely, this technique is useful for the elimination of contamination in the nucleic acid amplification area. Elimination of unwanted contamination has made gene probe analyses much more reproduceable.

Abstract: Nucleic acid probes and primers are described for detecting fungi that cause disease in humans and animals, as well as spoilage of food and beverages. These probes can detect rRNA, rDNA or polymerase chain reaction products from a majority of fungi in clinical, environmental or food samples. Nucleic acid hybridization assay probes specific for Aspergillus fumigatus, Blastomyces dermatitidis, Candida albicans, Coccidioides immitis, Cryptococcus neoformans, Histoplasma capsulatum, Aspergillus flavus, Aspergillus glaucus, Aspergillus niger, Aspergillus terreus, Candida glabrata, Candida guilliermondii, Candida kefyr, Candida krusei, Candida lusitaniae, Candida parapsilosis, Candida tropicalis, Pseudallescheria boydii, and Sporothrix schenckii are also described.

Abstract: A fluid delivery system for aspirating liquid from a bottle and conveying the liquid to an analytical instrument while allowing ambient air or gas to enter the bottle to replace the aspirated liquid. The bottle opening is sealed by a valve. A tube extends from the valve to the liquid within the bottle. A coupling component is removably connected to the analytical instrument and to the valve for operatively connecting the instrument to the tube.

Abstract: A method and apparatus for aspirating and dispensing a sample fluid. The apparatus includes an air source having an output port coupled to a first port of a flow through pressure transducer. A second port of the flow through pressure transducer is coupled to a first port of a sample probe. The flow through pressure transducer provides transducer signals to a detector circuit. In response to the transducer signals provided thereto, the detector detects the occurrence or non-occurrence of a plurality of different events.

Abstract: The invention features a sample probe and reagent selector valve that enables selection among multiple functions of withdrawing a biological sample from a syringe or capillary into a fluid parameter sensor module, providing calibration and quality control reagents to the sensor module, and flowing a washing fluid through intake passages to prevent cross-contamination and clogging. The valve and sensor module are used in conjunction with an automated analytical instrument, such as an automated blood analyzer, to increase the speed of the analysis, minimize cross contamination between samples, and to overcome the inherent dangers of using the conventional needle/syringe or capillary methods of withdrawing fluids to be tested. The design of the valve provides performance benefits in the form of lower sample and reagent waste volumes, elimination of auxiliary valves and manifolds, and superior performance and reduced cost.

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 subunits 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: An evanescent wave system and method including an optical sensor for use in assaying a reference material and at least one molecular species or analyte in a test medium or test sample for diagnostic and other applicable purposes. The sensor includes a waveguide for propagating a radiation input along its length. The radiation input causes evanescent electromagnetic waves that are capable of stimulating output emissions that are indicative of a reference material and of one or more molecular species or analytes. By comparing the emission(s) indicative of the reference material to the emission indicative of the presence of the molecular species or analyte, the presence and concentration of the molecule in the sample can be determined. The reference material provides for normalization and/or calibration of the system.

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: The detection of the IS6110 insertion element in a clinical specimen is a rapid way of diagnosing infection by Mycobacterium tuberculosis. A reliable diagnostic test for tuberculosis based on the IS6110 DNA is described in this disclosure. A "Universal" specimen preparation protocol that eliminates live organisms and purifies nucleic acids from all types of clinical specimens is described. Two nucleic acid primers designed to amplify IS6110 DNA with high specificity in a polymerase chain reaction are also described. The amplified IS6110 DNA is identified by a restriction endonuclease and electrophoresis based assay. The identification process also renders the DNA unamplifiable in a subsequent PCR, thereby reducing the possibility of contaminating other specimens. Time, labor and cost is minimized, while user safety and test reliability are maximized.

Abstract: The present invention provides apparatus and methods for determining the concentration of sample components of a sample by an analytical technique that yields a spectrum that can be written as Y(.omega.)=P(.omega.).multidot.C. The apparatus and methods of the invention account for experimental errors that give rise to distortions in the observed spectrum and that consequently result in inaccurate determinations of sample component concentrations. The invention accounts for such errors by modeling the total experimental error as the sum of one or more types of errors that can be written as .xi..multidot.K. The spectrum is then modeled as Y=P.multidot.C+.xi..multidot.K. Using the observed spectrum, known values for P, and a mathematical model for .xi., this equation can be solved for the best fit value of the sample component concentrations, C, and the magnitudes of the errors, K. The method can be used for any error that can be modeled in the foregoing manner, such as a shift in the spectrum.

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: Herein disclosed are methods for prenatally assessing risks of a pregnancy being affected by Down syndrome by testing maternal urine samples for levels of urinary gonadotropin peptide (UGP) elevated above normal. The methods employ immunoassays that are highly specific for UGP and have molar cross-reactivities of less than about 10% with intact hCG, with .beta.-subunit hCG, and with .alpha.-subunit hCG. The immunoassay methods of this invention are useful to test first trimester maternal urine samples. Among other benefits, first trimester prenatal screening provides the opportunity to terminate the pregnancy at an early gestational age, in the case of an unfavorable outcome.

Abstract: A solid state, 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 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.