Abstract: An improved luminometer is provided which uses a top loading plate carrier which receives a microtitration plate and uses a mask having an aperture corresponding to each test cell in the plate carrier. When the mask rotates downwardly to cover the microtitration plate, the plate carrier automatically orients the microtitration plate in the X, Y and Z directions. Reagents are added to the individual test cells through the mask aperture. Each reagent injector is extendable and retractable so that liquids can be added below the mask aperture during purging or washing and then the injector retracted. A pump is provided for each injector which is driven by a stepper motor and a rack and pinion connection to a syringe.

Abstract: Devices for the detection of small quantities either of divalent inorganic mercury ion (Hg.sup.2+) or of both Hg.sup.2+ and monomethyl mercury in water are disclosed. These devices comprises a bioluminescence detecting means and a bioluminescent biosensory microorganism cells, that emit significant light only when exposed to either to Hg.sup.2+ or to Hg.sup.2+ or momomethyl mercury. Plasmid cassettes and host microorganisms containing such cassettes are also disclosed The plasmid cassettes comprises a lux gene operon complex from Xenorhabdus luminescens. The lux operon complex comprises luxC, luxD, luxA, luxB, and luxE genes but is free of (1) a promoter for the complex and (2) an inducible regulatory gene for the complex.

Abstract: This invention is directed to a process for performing a competitive, electrochemiluminescence assay for endotoxins. In particular, the invention involves the use of ruthenium (II)tris-bipyridine NHS ester label to detect the labeled endotoxins.

Abstract: Chemiluminescent electron-rich aryl-substituted 1,2-dioxetane compounds are disclosed in which the aryl group is poly-substituted with suitable electron-donating groups such that the light-emitting pattern of the molecule results in a very high luminescent count, thus providing for a sensitive and precise assay for haptens, analytes, polynucleotides and the like. These substituted aryl-containing 1,2-dioxetane compounds can be used as direct labels in an immunoassay or when derivatized with an appropriate leaving group, can be used as a substrate for a enzyme immunoassay. The unusual chemiluminescence of the compounds allows the timing of the luminescent reaction to be exactly controlled.

Abstract: A cell storing a sample prepared by adsorbing an immunocomplex which is formed by antigen-antibody reaction on a surface of a noble metal colloid such as a gold colloid as an immunity test material is irradiated with excitation light from a light source by an optical system. Raman scattering light generated from the sample is guided to and detected by a spectral detector through an optical system. A signal processing arithmetic unit corrects the Raman scattering light which is detected by the spectral detector with an output of the detector indicating intensity of the light source for obtaining a Raman spectrum, thereby identifying or determining a measuring object material.

Abstract: A method for on-line assay in column chromatography of a property that requires appreciable time for sensitive measurement has the steps of separating the effluent into discrete fractions at equal time intervals, sequentially passing each fraction through each of a series of detectors, while preventing each fraction from mixing with another; and, for each fraction, calculating the assay from the information provided by each detector during the time interval the fraction passed through it.

Abstract: A portable toxicity tester for use in the field using bioluminescent organisms consisting of a light tight container for housing the necessary flash of light detecting apparatus and the necessary signal processing circuits, digital readout and control panel. A light tight chamber is provided with a removable stirrer assembly which is the stirrer motor housing as well as the light tight cover for the chamber. With the cover removed, a vial containing the necessary inoculated bioluminescence organisms is inserted into a holder in the chamber. Part of the stirrer assembly is a paddle attached to the motor shaft that extends to near the bottom of the vial. The top of the vial holder extends beyond the outer surface of the cover to insure a light tight seal.

Abstract: A system for measuring toxicity levels of a solution includes a water proof sample container transparent to visible light which holds an aqueous test solution containing bioluminescent organisms. A light tight chamber has a cavity which holds the sample container and includes a light port. A stress generating system positioned in the sample container generates pressure pulses which stimulate the organisms to generate light emissions. A light detector system mounted to the light tight chamber in a light tight manner detects light emissions generated in the sample container which propagate through the light port and are received by the light detector system. The light detector system generates an electric pulse in response to detecting each detected light emission. A controller enables the stress generating system and the light detector system, and then counts the electric pulses within a predetermined period of time.

Abstract: An apparatus for conducting measurements of electrochemiluminescence including a movable sample container support in the form of a carousel having a plurality of spaced apart support positions, an electrochemiluminescence testing device, a motor system to move the sample container support in a predetermined sequence, a sample transfer device to transfer sample from containers in the support positions to the testing device, and a detection system to detect the presence of a sample container and to produce an actuation signal based on the detected presence of the sample container.

Abstract: A method for detecting an analyte, in an aqueous solution at a physiological pH, by reductive or oxidative/reductive electrochemical luminescence methodologies is disclosed. The method proceeds by labelling the analyte with a transition metal complex, followed by inducing the transition metal label to luminescence by application of a suitable electrical potential to a solution containing the label and the analyte. The transition metal complex can be a tris-ruthenium(bipyridine) complex. A hydroxylamine and/or a halogen-containing moiety can be used to enhance both reductive and/or oxidative electrochemical luminescence of the transition metal complex. The transition metal chelate can be used as a label for the detection of picomolar concentrations of an analyte of interest, such as an analyte present in a sample of a physiological fluid.

Abstract: The invention addresses a measuring cell and a process for carrying out electrochemiluminescence measurements (ECL). The measuring cell has a sample space in which there are disposed a working and a counter electrode. The counter electrode is disposed such that it is located in the light path between the working electrode and the optical detector.

Abstract: The rate of a biomolecular reaction, such as an enzymatic reaction or an affinity binding reaction, is measured using electrochemiluminescence ("ECL"). The reaction is conducted in an electrochemical cell with a mixture of reagents including a luminophore which will relate the concentration of a reactant, a reaction partner or the reaction product of a reaction partner to the ECL intensity. The reaction partner is a reagent which reacts with the reactant and which participates with the luminophore (or its reaction product participates with the luminophore) to cause the emission of ECL. The ECL intensity is modulated with a series of electrical pulses which are applied to the mixture of reagents at a preselected potential and for preselected intervals of time and duration. The ECL intensity is measured at the same intervals to provide a timed series of values (P).

Abstract: Apparatus for measuring liquid aldehydes includes a liquid sample pouring mechanism for dividing a liquid sample which contains aldehydes into a formaldehyde measuring liquid sample and a total aldehyde measuring liquid sample and pouring the liquids separately from each other; a formaldehyde measuring mechanism for measuring the liquid formaldehyde in the formaldehyde measuring liquid sample; a total aldehyde measuring mechanism for measuring the liquid aldehydes in the total aldehyde measuring liquid sample; and a formaldehyde ratio calculating mechanism for calculating the ratio of the formaldehyde to the total aldehyde from the results of the measurements of the respective aldehyde measuring mechanisms.

Abstract: A composition and method for enhancing luminol chemiluminescence assays for superoxide anion comprising an orthovanadate salt, such as sodium orthovanadate. Orthovanadate enhances photon emission when luminol is cleaved by superoxide anion. The orthovanadate salt is non-cytotoxic and non-denaturing to intact cells. A method comprises reacting luminol in the presence of an orthovanadate anion with an analyte suspected of containing superoxide anion and measuring the photon output. A kit comprises a predetermined mount of luminol and orthovanadate.

Abstract: A method for making a composition for measuring the concentration of chloated aromatic compounds in aqueous fluids, and an optical probe for use with the method. The composition comprises a hydrophobic polymer matrix, preferably polyamide, with a fluorescent indicator uniformly dispersed therein. The indicator fluoresces in the presence of the chlorinated aromatic compounds with an intensity dependent on the concentration of these compounds in the fluid of interest, such as 8-amino-2-naphthalene sulfonate. The probe includes a hollow cylindrical housing that contains the composition in its distal end. The probe admits an aqueous fluid to the probe interior for exposure to the composition. An optical fiber transmits excitation light from a remote source to the composition while the indicator reacts with chlorinated aromatic compounds present in the fluid. The resulting fluorescence light signal is reflected to a second optical fiber that transmits the light to a spectrophotometer for analysis.

Abstract: Embodiments of the invention provide methods of preparing an activated acridinium microparticle. Generally, the methods involve direct covalent coupling or an affinity format. The direct covalent coupling method involves coating a microparticle with a proteinaceous compound. Then, a 10-methyl-N-tosyl-N-(2-carboxyethyl)-9-acridinium carboximide trifluoromethane sulfonate is coupled to the proteinaceous compound. In the affinity format, a microparticle is coated with a biotinylated proteinaceous compound. The microparticle is reacted with an anti-biotin labelled 10-methyl-N-tosyl-N-(2-carboxyethyl)-9-acridinium carboximide trifluoromethane sulfonate. Methods are also provided for using such a microparticle. Those methods of use can estimate transfer efficiency, calibrate optics, and measure membrane pore size of a chemiluminescence based instrument. Test elements for analytical instruments are also provided.

Abstract: An apparatus as provided for use in carrying out electrochemiluminescence test measurements. The apparatus includes a cell to contain an electrochemiluminescence sample fluid. A working electrode is provided within the cell and is coupled to a supply of electrical energy to apply the same to the sample fluid. A temperature effect adjustment system serves either to adjust a temperature of the electrochemiluminescent sample fluid so that it is within a predetermined range, or else adjusts an output signal representing light produced through electrochemiluminescence of the sample fluid based on the temperature of the sample fluid.

Abstract: The signal generated in a specific binding assay wherein a peroxidase label is used to detect the resulting specific binding complex on a microporous filtration membrane can be modulated by contacting the signal forming reagents with a buffered solution of a hydroxamic acid or acyl hydrazine having the structureR--CO--NH--R'or an equivalent salt thereof, wherein R is aryl of 6 to 10 carbon atoms in the aromatic nucleus, alkyl of 1 to 7 carbon atoms or cycloalkyl of 5 to 10 carbon atoms in the ring, and R' is hydroxy or amino. This solution can be provided in a diagnostic test kit for use in various methods to detect a specific binding ligand. The result is improved signal stability and lowered background after the use of a high pH wash solution in the assay.

Abstract: A chemiluminescent detector having a first reflective layer; a second transparent layer; the first reflective layer having cut therein a first sample flow path; an exhaust flow path and a reagent flow path, said sample reagent and exhaust flow paths having at least one capillary channel joining the sample and reagent conduits such that the sample and reagent conduits can mix in the exhaust conduits at a plurality of discrete points and create a plurality of chemiluminescent reactions.

Abstract: A method and apparatus for determining a plurality of substances or constituents of a specimen sample includes the steps of placing a single specimen sample in a reaction vessel or test tube and adding at least two reagents to the reaction vessel to form a detectable product and then initiating a reaction within the vessel and provide an emission of light energy in a predetermined spectral range. The reaction vessel is disposed in a chamber of a housing and a plurality of detector assemblies are disposed about the housing with portions of the detector assemblies disposed through the housing and exposed to the reaction vessel. Each of the detector assemblies receives a portion of the light emission and feeds such portion to a detector.

Abstract: A luminescence measuring system comprises an apparatus for supplying samples located in separate test tubes. In the measuring chamber of a luminometer, the samples are in turn presented to a light detector, such as photomultiplier. Two mutually displaceable components, which are cup-shaped and fit into one another with the cup bottoms facing outwards, define the measuring chamber. The component shells are provided with holes which can be aligned by relative displacement of the components so as to admit the test tube into the luminometer and the measuring chamber and subsequently to discharge it therefrom under the action of gravity. The test tubes are conveyed to the luminometer by a sleeve-chain conveyor having a bottom with a through hole.

Abstract: There is disclosed a device capable of continuously measuring the presence and concentration of an analyte or analytes and a method for using said device in a liquid and/or a gas phase reaction volume. The inventive device comprises a sensor probe, a reservoir, and a detector. The inventive device delivers reagent to the sensor probe in a flow method to directly and continuously renew reagent, thereby allowing the continuous measurement of the presence and the concentration of an analyte or analytes.

Abstract: An NO radical measuring method comprising the steps of mixing a test sample solution containing NO radicals with hydrogen peroxide or an analogous substance thereto and luminol or an analogous substance thereto, and measuring the intensity of chemiluminescence. The method enables a trace amount of NO radical to be measured with accuracy and in real time. An apparatus used for this method is also disclosed.

Abstract: The present invention relates to a chemical luminescence-detecting apparatus that is provided with a plurality of optical detectors different in sensitivity in the vicinity of a photometric cell. A ratio of outputs from the optical detectors based on intensity of luminescence is previously determined and stored. Signal processing can multiply an output of a low sensitivity optical detector by a factor determined by the stored ratio to measure the intensity of luminescence so that a conversion value corresponding to an equivalent output from a high sensitivity optical detector may be obtained when the output from the high sensitivity optical detector has become saturated.

Abstract: The use of bioluminescence on a filtration enrichment sample and a light measuring device allows microbial monitoring in liquids without sample incubation. All characteristics of this monitor are zero gravity compatible which makes it particularly suitable for applications such as monitoring microbial counts in water in a zero gravity, closed environment.

Abstract: A luminometer comprising a tray for receiving an array of sample wells, a photodetector assembly, and device for relatively moving the tray and photodetector assembly in one direction to align the sample wells received by the tray in a predetermined sequence with the photodetector assembly. The photodetector assembly of the luminometer includes a stage, a photodetection head having a detection aperture permitting passage of light therethrough, a device for mounting the photodetection head to the stage that permits movement of the head in a direction substantially normal to the direction of relative tray and photodetector assembly movement, and a device for biasing the photodetection head toward a selected sample well so that the detection aperture is substantially isolated from light emitted from adjacent wells. Internal and external photodetector calibration systems and a sample heater are also contemplated.

Abstract: A method for enhancing luminol chemiluminescence assays for superoxide anion comprising an orthovanadate salt, such as sodium orthovanadate. Orthovanadate enhances photon emission when luminol is cleaved by superoxide anion. The orthovanadate salt is non-cytotoxic and non-denaturing to intact cells. A method comprises reacting luminol in the presence of an orthovanadate anion with an analyte suspected of containing superoxide anion and measuring the photon output. A kit comprises a predetermined amount of luminol and orthovanadate in separate containers.

Abstract: Apparatus for preconcentrating trace amounts of organic vapors in a sample of air for subsequent detection, comprising a metallic substrate; a thin film of fullerenes deposited on the metallic substrate for adsorbing the organic vapors on the thin film of fullerenes, thereby preconcentrating the organic vapors; and apparatus for heating the metallic substrate to a predetermined optimum temperature for desorbing the vapors from the thin film of fullerenes to form desorbed organic vapors for subsequent detection.

Abstract: The invention describes an assay device and assembly for detecting an analyte in a liquid sample. Each assay device in the assembly includes structure defining a well, a ligand-coated particle, and a flexible particle retaining structure for holding the particle in a captured position within the well.

Abstract: A multi-layer blood culture sensor includes two matrices. The first matrix is a polymer that is permeable to carbon dioxide and water, but impermeable to protons. A pH sensitive absorbance based dye is encapsulated or isolated in the polymer. The second matrix is a polymer with a pH insensitive fluorescent dye encapsulated or isolated in the polymer. The matrices are spectrally coupled and are useful for the determination of microorganisms in a blood culture bottle.

Abstract: A dry analytical element can be used to sensitively and rapidly detect a wide variety of specific binding ligands in either a competitive binding or sandwich assay format. The assays are carried out using a peroxidase-labeled immunoreactant. The peroxidase label is stabilized with a 4-hydroxy or 4-alkoxyarylacetamide which is located in one or more zones of the element. Not only is the label stabilized with the stabilizer, but the assay is more sensitive.

Abstract: An electronic device for measuring extremely faint light emissions comprises a photomultiplier tube surrounded by a sleeve made of a material which is a good heat conductor, cooled to a low temperature and insulated from the outside, a thermally insulating and optically transparent lightguide body being stably glued to the photocathode of the photomultiplier tube to receive the light radiation emitted by a specimen to be examined, which is inserted in a cavity of a supporting structure holding a rotary body which can be turned in front of the lightguide body, so as to operate as a shutter for the lightguide in a first turned measurement position thereof to allow measurement of the dark signal and then allow, as the rotary body and the specimen held therein are turned to a second measurement position, to measure the light emission from the specimen.

Abstract: A process is provided for analyzing and detecting in an aqueous based mobile phase sample one or more N-nitroso compounds, which process includes the steps of injecting the aqueous based sample into a high pressure chromatograph to produce a liquid effluent where the nitroso compounds are resolved and separated, mixing the liquid effluent with an inert gas to produce a biphasic gas/liquid mixture, irradiating the biphasic mixture under ultraviolet irradiation to convert the nitroso compounds to nitric oxide gas, and detecting the nitric oxide produced.

Abstract: An NO.sub.x analyzer capable of reducing maintenance operations for removing solid substances from the analyzer, and for obtaining an analytical value of improved reliability for sample gases flowed through the analyzer is provided. A sample gas supply passage on the downstream side of an NO.sub.x convertor is provided with a first capillary therein; a sample gas supply passage between the first capillary and the NO.sub.x convertor is provided with an overflow passage having a second capillary branch connected therewith; a sample gas supply passage on a downstream side of the first capillary is provided with a diluent air supply passage having a third capillary therein and also branch connected with the sample gas supply passage. At least the confluence of the first capillary, the second capillary, and the diluent supply passage with the sample gas supply passage is arranged within a heating zone of the NO.sub.x analyzer.

Abstract: Red-shifted, water-soluble, fluorescent, monomerically-tetherable derivatives having the formula: ##STR1##wherein, M represents either H.sub.2 or is selected from among the following metals: aluminum, silicon, phosphorus, gallium, germanium, cadmium, scandium, magnesium, tin, and zinc. Each R.sub.1 is independently selected from --XYW, --YW, and --W. X represents either a carbon, or heteroatom selected from among oxygen, nitrogen, sulfur, phosphorus, silicon, and selenium; Y represents a linking group; and W represents a water solubilizing group. The substituent R.sub.2 is selected from among --A, --Y'A, --XA, and --XY'A, where A denotes a biological entity such as an antibody, antibody fragment, nucleotide, nucleic acid probe, antigen, oligonucleotide, deoxynucleotide, dideoxynucleotide, avidin, streptavidin or membrane probe, or R.sub.2 is a reactive or activatable group suitable for conjugating to a biological entity.

Abstract: A diagnostic microbiological testing apparatus and method includes at least one test tray including a plurality of reaction chambers, a light source disposed proximate to the test tray for directing light, at an excitation wavelength of a fluorescence emitting agent contained within the reaction chambers, at the test tray, a filter for passing therethrough only light generated by a fluorescence emitting reaction resulting from the interaction of the fluorescence emitting agent and a sample, and an imaging mechanism for detecting only the light generated by the fluorescence emitting reaction at the emission wavelength simultaneously from the plurality of reaction chambers.

Abstract: The present invention describes the process and apparatus for the simultaneous measurement of sulfur-containing compounds and organic compounds with or without sulfur in their structures. A detector cell is described that allows simultaneous measurement of compounds that can be ionized in a flame and thereby cause the electrical conductivity of the flame to increase, and the selective measurement of sulfur-containing compounds which simultaneously form sulfur monoxide. Sulfur monoxide, upon mixing with ozone, emits light from 240 to 450 nm. The intensity of the light can be measured and related to the concentration of sulfur in the sample, while changes in electrical conductivity of the flame measured by imposing a voltage across the cell quantifies the organic compounds irrespective of whether or not they contain sulfur.

Abstract: A method and device for measuring the binding affinity of a receptor to a ligand. According to one aspect of the invention, arrays of polymers are synthesized or immobilized on a substrate (212). The array of polymers is exposed to a fluorescently-labelled receptor in solutions of varying concentration. The fluorescence intensity of the labelled receptor is measured by way of, e.g., a photon counter using a confocal microscope (316). Binding affinity is determined through analysis of the relationship between fluorescence intensity and the solution concentration of the receptor. On-rates are measured as a kinetic increase in surface fluorescence intensity, and the on-rate constant rate extracted from fits to the data.

Abstract: An automated immunoassay analyzer includes a computer controlled instrument (10) and display (16). The display (16) provides a real-time presentation of all operations being performed within the instrument (10). A large number of samples can be loaded into the instrument (10), and the order of testing the samples can be rearranged according to a priority determined by the operator at any time. A wide variety of immunoassays can be performed on each sample and several different immunoassays can be performed on any one sample. Information related to the type of immunoassays being performed on particular samples is collected by a bar code reader (44) and this information is conveyed to the computer (12) for presentation on the display (16). The computer (12) tracks the progress of each immunoassay through the reaction circuit to the detection station (46).

Abstract: The present invention relates to a method and an apparatus for measuring trace quantity of oxygen in a gas by reacting yellow phosphorus vapor and oxygen in a sample gas, and measuring the intensity of the light emitted by the reaction. Together with the sample gas, a constant amount of oxygen is continuously supplied to a reaction chamber so as to react with the yellow phosphorus vapor, and the intensity of the light emitted is measured. The oxygen concentration in the sample gas is determined from the difference between the value measured as above and the intensity of the light emitted by the reaction between the yellow phosphorus vapor and the added oxygen, or from the oxygen concentration obtained from the measured value and the concentration of the added oxygen.

Abstract: A process and apparatus for the simultaneous measurement of sulfur-containing compounds and organic compounds with or without sulfur in their structures. A detector cell allows simultaneous measurement of compounds that can be ionized in a flame and thereby cause the electrical conductivity of the flame to increase, and the selective measurement of sulfur-containing compounds which simultaneously form sulfur monoxide. Sulfur monoxide, upon mixing with ozone, emits light from 240 to 450 nm. The intensity of the light can be measured and related to the concentration of sulfur in the sample, while changes in electrical conductivity of the flame measured by imposing a voltage across the cell quantifies the organic compounds irrespective of whether or not they contain sulfur.

Abstract: A chemical moiety is disclosed which comprises a chemical, biochemical, or biological substance attached to one or more electrochemiluminescent organometallic compounds. In a preferred embodiment of the invention the substance is attached to one or more ruthenium-containing or osmium-containing luminescent organometallic compounds. Methods are disclosed for detecting low concentrations of the chemical moiety using chemiluminescent, electrochemiluminescent, and photoluminescent means. Compounds are disclosed which are useful for labeling substances of interest with ruthenium-containing and osmium-containing labels or other electrochemiluminescent labels. These labeled substances are useful in methods provided for detecting and quantifying analytes of interest in binding assays and competitive binding assays. The labeled substances are of particular use in homogeneous binding assays.

Abstract: The present invention provides a process of quantifying the number of viable cells in an aqueous suspension of cells using an energy-emitting non-hazardous probe and a probe-trigger. The process provides quantification data in short periods of time without the use of hazardous materials. A process of the present invention can also be used to quantify negatively charged particle number, assay for cytotoxicity, assay for cell proliferation and assay for cell differentiation. Still further, the present invention provides an assay kit for quantification of cells or negatively charged particles.

Abstract: A method and apparatus for triggering and measuring electrochemiluminescent phenomena using a voltage waveform applied at the voltammetric working electrode which improves the precision and accuracy of measurements. This waveform has a decreasing scan rate in the range of voltages for which electrochemiluminescence is triggered and is substantially sinusoidal in shape in this range. The waveform results from locating the reference electrode of a potentiostat in close potential proximity to its counter electrode, and applying a uniform scanning voltage waveform at the reference electrode. The waveform also can be synthesized digitally, converted to analog form, and applied directly to the working electrode with the reference electrode in close potential proximity to the working electrode.

Abstract: A chemical sensor consists of(a) a solid substrate,(b) a layer (D) which is applied to the substrate and contains one or more fluorescent compounds and(c) a layer (A) which is applied to the layer (D) and contains one or more coupling components (K) which, as a result of reacting with the analyte, give rise to one or more specific absorption bands, some or all of which overlap in the spectrum with the emission of the fluorescent compound of layer (D).

Abstract: A radiation measuring apparatus for performing measurements on samples contained in a plurality of sample containers disposed in the form of a matrix on a holder plate, the apparatus including a radiation detector having an entrance window, displacement devices for aligning successive sample containers with the entrance window of the radiation detector for automatic measurement of samples in the sample containers, the radiation detector and the sample containers being movable relative to one another in such a way that the sample container being measured and the entrance window of the detector are disposed coaxially with each other.

Abstract: The concentration of an organic chlorine compound contained in a gaseous medium is measured in situ by feeding the gaseous medium to a reaction zone and oxidizing the chlorine compound to produce a reactive gas capable of reacting with a chemiluminescent compound to cause chemiluminescence. The reactive gas is contacted with the chemiluminescent compound contained in a cell to cause chemiluminescence whose intensity is proportional to the amount of the reactive gas produced by the oxidation of the organic compound. The concentration of an organic chlorine compound contained in an aqueous medium may also be measured by the similar method after separating the organic chlorine compound as vapors from the aqueous medium. A device suitable for the above measurement is also disclosed.

Abstract: In a chemiluminescent analyzer for measuring a concentration of an object gas in a sample gas by mixing the sample gas with 5 a reaction gas and measuring light generated in a chemical reaction between the object gas and the reaction gas, the two gases flow through a double tube composed of an outer tube and an inner tube, and are mixed at the end of the tubes. The end of the inner tube is closed, and one or more outlets are provided at the side wall of the inner tube near the closed end. The flow of the gas coming out of the inner tube through the outlet or outlets crosses the flow of the gas in the outer tube, which enhances the mixture of the two gases and increases the chance of reaction between the object gas and the reaction gas.

Abstract: A method and apparatus is provided for analyzing the leucocytes in a biological fluid. The biological fluid is passed through a filter material having a critical wetting surface tension greater than 53 dynes/cm so that the leucocytes are held in the filter by adsorption. The filter material is subsequently treated with luminogenic material so that the treated filter may be analyzed by luminescence detection.

Abstract: In one exemplar embodiment, a chemiluminescent nitrogen detector for detecting chemically-bound nitrogen in an organic compound is provided in which a discrete sample of the organic compound containing the chemically-bound nitrogen is injected into a high temperature furnace where the sample is pyrolyzed at extremely high temperatures in an oxygen rich atmosphere to form nitric oxide. The pyrolysis gases, including nitric oxide is then applied to a drying means for eliminating a substantial quantity of water vapor from the carried pyrolysis gases to insure that the dew point of the gases is below the operating temperature of a nitric oxide and ozone reaction chamber. The nitric oxide and ozone are mixed in a reaction chamber to form metastable nitrogen dioxide which instantaneously relaxes to its ground state with a resulting photo-emission of light energy.