Abstract: A method and device for evaluating the quantities of adsorbed impurities in sample gas of ultra-high purity for various kinds of materials. After inert gas of ultra-high purity is supplied to a sample-gas pipe(16) through a purifier(1)(a first gas-supply source), the inside of said sample-gas pipe(16) is baked by heater(19 to 20)(heating means). The inside of sample-gas pipe(16) is kept in an atmosphere at specified temperature and then changeover valves(9, 10) are changed over from opening to closing or vice versa so that the sample gas of a specified concentration is supplied from a bomb(6)(a second gas-supply source)into the sample-gas pipe(16) until the quantities of adsorbed impurities reach saturation, in other words, from the time when, sample gas flows into the pipe to that when a microanalyzer(25) detects said gas of said specified concentration.

Abstract: A method for preparing a solventless protein standard is disclosed in which a solventless dye indicator and a predetermined amount of solventless protein are placed in an appropriate receptacle such as the well of a multiwell plate. This results in a solventless protein standard in which the solventless protein and the solventless dye are contained within the same receptacle. When an appropriate solvent is added to the receptacle, the protein and dye react together to produce a color change which is detectable, and which can be used as a standard for a protein assay using that dye. Also claimed is the solventless protein assay standard produced by the process.

Abstract: A reagent system for accurately determining the volume of a pipette using a photometer is disclosed. The reagent system for use with the photometer includes a first container holding a reference solution and at least one second container holding a sample solution. A container holding the reference solution having maximum absorbance at a first wavelength is positioned in the photometer. The absorbances of the container at the first wavelength and at a second wavelength are measured. Then the optical pathlength of the container at the second wavelength is calculated from the measured absorbances at the first and second wavelengths. An aliquot of the sample solution is introduced into the container with a pipette to be calibrated. The sample solution has maximum absorbance at the second wavelength. The sample solution is mixed with the reference solution to form a mixture. Then the absorbance of the mixture in the container is measured at the second wavelength.

Abstract: The present invention provides a compact, highly automated photometric analyzer for measuring the concentration of substances found in a fluid, typically a blood sample or other body fluid sample taken from a patient. The operator places a small quantity of the sample into a special rotor and then loads the rotor into the analyzer. The analyzer accepts the rotor, centrifuges and dilutes the sample, and distributes the sample into a plurality of cuvettes near the outer edge of the rotor. Some of these cuvettes hold reagents which react with the sample. The analyzer then measures light absorption within the sample at a number of preselected frequencies. According to the present invention, a pair of specially designed apertures direct light from the sample through a plurality of beam splitters, interference filters, and associated photodetectors. The system also includes means for performing automatic calibration and error checking functions.

Abstract: There is described a positive calibrator/control composition for use in assays for the detection of antibodies to infectious disease agents. The composition includes a composite antibody of a nonspecific IgM immunoglobulin moiety covalently linked to a specific, non-IgM antibody moiety. Also described is an assay method which utilizes the positive calibrator or control composition.

Abstract: The present invention concerns a method for the stabilization of proteins in an aqueous solution which is characterized in that one or several members of the heat shock protein (Hsp90) family are added to the aqueous solution containing protein.

Abstract: Appendicitis can be detected in human beings suspected of having appendicitis by determining a threshold level of 10 mg/liter of .sigma.-hydroxyhippuric acid in the urine of such humans. This threshold level can be determined by qualitative, semiquantitative, or quantitative methods including HPLC (high pressure liquid chromatography), TLC (thin layer chromatography), radioimmunoassay, colorimetric tests, NMR (nuclear magnetic resonance), mass spectrometry, electrophoresis, monoclonal antibody tests, and enzymatic tests. The absence of appendicitis can be established by the presence of .sigma.-hydroxyhippuric acid in concentrations less than about 10 mg/liter in a urine sample.

Abstract: A method and composition for fixing and stabilizing tissues, cells, and cell components such that the antigenic sites are preserved for a useful period of time. The fixative employs a formaldehyde donor that is non-toxic, non-flammable, and that stabilizes the cell with minimal damage to and alteration of the cell morphology. In particular, the cell antigenic sites are left intact so that studies with monoclonal antibodies may be conducted. The invention also discloses a method for developing a positive control for test reagents and for test instrumentation.

Abstract: A method for the analysis of a medical sample, particularly a body fluid, with the aid of an analyzing instrument, in which a test fluid, which contains an aliquot part of the sample and reagents, is in an optical cuvette and the temperature of the test fluid is determined in the cuvette. In order to determine the temperature of the test fluid directly and without contact, in a temperature calibration step the optical absorption of a calibrator fluid is determined at various temperatures at at least two wavelengths within the NIR range in order to obtain a calibration data set relating to the temperature-dependency of the optical absorption. In a temperature-measuring step the optical absorption of a test fluid of unknown temperature is measured at the same wavelengths and its temperature is determined by comparison of the absorption data obtained in the measuring step with the calibration data set.

Abstract: A method in a computer system for modeling a three-dimensional structure of a model protein is provided. In a preferred embodiment, the modeling is based upon a three-dimensional structure of a template protein and an amino acid sequence alignment of the model protein and the template protein. The proteins comprise a plurality of amino acids having backbone atoms and side chain atoms. For each amino acid in the model protein, when the template protein has an amino acid aligned with the amino acid of the model protein, the position of each backbone atom of the amino acid of the model protein is established based on the position of a topologically equivalent backbone atom in the aligned amino acid of the template protein. The inter-atomic distance constraints for each pair of atoms with an established position is generated. Finally, the position of each atom in the model protein is set so that the inter-atomic distances are in accordance with the constraints.

Abstract: Disclosed is a serum free control reagent formulation useful for the determination of a pre-selected analyte. The formulation involves an aqueous solution of a predetermined amount of the analyte together with a polymerized quaternary salt of di- or mono- allyl, di- or tri- alkyl ammonium characterized by the formulae: ##STR1## where R is straight or branched chain alkyl of 1 to 4 carbon atoms, n is a number of at least 9 and .theta. represents a counteranion. The formulation typically contains a buffer to maintain its pH at a level of about 7.5 and a preservative.

Abstract: Various methods are described for producing volumetric one-component iodine-free Karl Fischer reagents useful for determining the water content of a sample, the reagents containing triiodide as the dominant oxidizing species. The reagents contain a reducing agent such as SO.sub.2, a buffer such as amine, a solvent, and an oxidizing agent that is triiodide, generally in the form of triiodide ions. The molar amount of SO.sub.2 in these reagents is greater than the molar amount of triiodide. The characteristics of these methods generally include the formation of triiodide in a first solution having a first amine/SO.sub.2 ratio prior to obtaining a final solution having the final amine/SO.sub.2 ratio. These methods provide economies in the ingredients used, and yield reagents exhibiting good liter strength and enhanced reproducibility of properties from one production run to the next.

Abstract: The present invention has multiple aspects that include an intermediate composition (i.e., a marked stock calibrator solution) for preparing diluted calibrator solutions that are marked in proportion to the amount of calibrator contained therein; a diluted (i.e., working) calibrator solution made therefrom, a series of diluted calibrator solutions that are visually colored in proportion to the concentration of calibrator therein; a method for performing a diagnostic assay that employs a series of marked calibrator solutions; a method for confirming that a stock solution of calibrator has been diluted correctly; and a method for indirectly confirming the concentration of calibrator in a working calibrator solution.

Abstract: A reagent composition which includes organic cationic dyes for staining the reticulocytes in a blood sample and buffer solutions for maintaining a pH of about 6 to about 9 is provided. The dyes may be the blue absorption dyes Oxazine 750 or New Methylene Blue. A zwitterionic surfactant is included in the reagent composition for isovolumetric sphering of the reticulocytes and erythrocytes. The reagent composition and whole blood sample mixture are passed through the sensing region of a flow cytometer. The light scattered and absorbed by each cell is measured; the erythrocytes can be distinguished from reticulocytes and the volume, hemoglobin concentration and the hemoglobin content of each reticulocyte or erythrocyte, and the mean cell volume, mean corpuscular hemoglobin concentration, and mean cell hemoglobin of the reticulocytes or erythrocytes are calculated from the measured cell-by-cell volume and hemoglobin concentration.

Abstract: This invention relates to an enzyme assay for quantitative analysis of biochemical substances using NAD(P)-NAD(P)H system and utilizing hydrogen peroxide, in which isocitric acid, metal ions and isocitrate dehydrogenase are previously added to a test sample, thereby consuming the endogenous substances that interfere the analysis, and at the same time regenerating NAD(P)H reduced.The isocitrate dehydrogenase is then inactivated by addition of a chelating agent, an enzyme or substrate that generates hydrogen peroxide as reaction product is added simultaneously or thereafter, and the amount of hydrogen peroxide thus formed is measured.Biochemical substances that generate hydrogen peroxide as reaction product can be correctly analyzed by this method with no adverse effect of endogenous substances because these interfering substances have been removed prior to measurement.

Abstract: An apparatus for supplying a solution of a powdery product as a specimen of viscosity measurement. The apparatus includes electronic discharge-weighing device (4) for determining the amount of the powdery sample in sample container (2), introduced into hopper (6) and discharged therefrom by vibration-generating drive (5); dissolution container (12) for receiving and dissolving the powdery sample from hopper (6); electronic balance (13)for weighing the powdery sample in container (12); supply source (14) for solvent into container (12); device (36) for heating and stirring the powdery sample and the solvent in container (12), and a control circuit for controlling the apparatus.

Abstract: A stable reticulocyte reference control which may be used with both manual and flow cytometric reticulocyte counting devices is provided. The reference control contains erythrocytes loaded with nucleic acids or polyanions capable of binding with a cationic dye. The loaded erythrocytes are suspended in an aqueous preserving medium. Methods of making and using the reticulocyte reference control are also provided.

Abstract: The present invention relates to a biosynthetic cerebrospinal fluid control and method of use. Additionally, this invention relates to the isolation and purification of stable liquid human prealbumin, a component in the biosynthetic cerebrospinal fluid control.

Abstract: A composition for detecting the presence and concentration of a substance such as uranyl, comprising an organohalide covalently bonded to an indicator for said substance. The composition has at least one active OH site for forming a complex with the substance to be detected. The composition is made by reacting equimolar amounts of the indicator and the organohalide in a polar organic solvent. The absorbance spectrum of the composition-uranyl complex is shifted with respect to the absorbance spectrum of the indicator-uranyl complex, to provide better spectral resolution for detecting uranyl.

Abstract: A cell fixative composition for fixing the internal components of a cell without disrupting the cell surface components is disclosed. The composition contains a compound for preserving intracellular morphology, a compound for fixing internal components of the cell, a compound which facilitates transportation of components across the cellular membrane, and a compound for increasing permeability of cell membranes. Methods for analyzing cells which have been fixed using the composition are also disclosed.

Abstract: Aqueous solutions containing buffers and electrolytes are adjusted to levels required for calibration of both blood gas analyzers and ion selective electrolyte analyzers. A control material, composed of similar matrix, is adjusted to three levels of blood gas and electrolyte conditions. These quality control materials are used to monitor blood gas/electrolyte laboratory instrumentation.

Abstract: A calibration system comprising a sensor cassette including at least one sensor to be calibrated and a housing having a liquid passage including a chamber. The housing is coupled to the sensor cassette to place the liquid passage in fluid communication with the sensor cassette. The housing has a gas injection passage through which a gas can be injected into the liquid passage to mix with a calibration liquid in the housing. A gas vent vents the gas from the housing. Porous media is provided in the chamber. The gas and calibration liquid pass through the porous media, and the porous media assists in rapid mixing of the gas and the calibration liquid.

Abstract: The present invention provides lyophilized reagent spheres comprising reagents suitable for analysis of biological samples, in particular analysis of blood samples in centrifugal analyzers. Also provided are diluents which are conveniently used in such analyzers.

Abstract: A reagent composition which include an organic cationic dye for staining the reticulocytes in the blood sample and a buffer solution for maintaining a pH of about 6 to about 9 is provided. The dyes may be the red excitable fluorescent dye Oxazine 750, or the blue excitable fluorescent dyes Acridine Orange or derivatives of Acridine Orange. A zwitterionic surfactant is included in the reagent composition for isovolumetric sphering of the reticulocytes and erythrocytes.

Abstract: Methods for determining the corrosivity of a substance to human skin or membrane are disclosed. In one approach, corrosivity is evaluated by measuring the time required for the test substance to transit a biobarrier that mimics human skin or membranes or the time required to cause a component of such biobarrier to break down and transit the membrane. The invention also envisions alternative approaches which involve series of layers of dyes and corrosive-resistant materials coated onto microspheres or test strips. Use of these methods provides a rapid determination of the corrosivity of test materials.

Abstract: The present invention provides a culture device for growing microorganisms having a self supporting substrate coated with a cold-water soluble dry powder which is a mixture of gelling agents and nutrients and a transparent cover sheet having a layer of a water-soluble pressure sensitive adhesive containing indicator dyes on a surface adjacent to the substrate wherein the improvement includes either adding a sufficient amount of a water-insoluble organic acid to the adhesive or including a sufficient amount of acrylic acid as a comonomer in the adhesive in order to inhibit or prevent a premature color change of the indicator dyes.

Abstract: A safe analytical technique for determining the concentration amount of dibutyl and monobutyl phosphate degradation products in the TBP-dodecane solvent used in solvent extraction processes. This method of chemical analysis eliminates the use of diazomethane, which is toxic and explosive, thereby providing a safer laboratory technique for routine analyses required to monitor production solvent extraction processes. The solvent sample to be analyzed is spiked with mass labelled, deuterated dibutyl and monobutyl phosphates, which act as internal standards. After adding a silylating agent, bistrimethylsilyltrifluoracetamide, the sample is injected into a gas chromatograph/mass spectrometer, which measures the ratio between the labelled internal standard and the naturally occurring material to obtain a quantitative result.

Abstract: A reagent denatures or eliminates factors interfering with biochemical reactions by simple treatment without requiring separation of any denatured product precipitate. The reagent makes it possible to assay, in particular, .beta.-glucan and endotoxin in blood-derived samples rapidly and efficiently with high sensitivity. The reagent includes a hexadimethrine compound and an alkali metal hydroxide or an alkali metal hydroxide as a main component. A method for assaying a substance specifically reacting with a Limulus reagent utilizing the reagent, an assay kit including at least the reagent and a Limulus reagent, and a method of diagnosing infectious diseases based on the results obtained by the assay method are also provided.

Abstract: Disclosed is a composition useful in the processing of blood and cerebrospinal fluid to help maintain sample integrity for analytical testing. The composition generally includes a first enzyme inhibitor selected from the group of enzyme inhibitors consisting of inhibitors which allow substantially the function of metalo-peptidase while inhibiting at least one enzyme selected from the group of enzymes consisting of endopeptidase, exopeptidase and sulfhydryl-mediated proteases, and inhibitors which substantially inhibit the function of metalo-peptidase, wherein where the first enzyme inhibitor inhibits metalo-peptidase, the assaying composition further comprises a second enzyme inhibitor suitable to inhibit at least one enzyme selected from the group of enzymes consisting of endopeptidase, exopeptidase, metalo-peptidase and sulfhydryl-mediated proteases. Further disclosed is an apparatus which includes a tube containing the inhibitors into which the bodyfluids are placed.

Abstract: A system for rapid microbead calibration of a flow cytometer including a suspension of quantitative fluorescent microbead standards and analytical software. The software is used to take information on the microbead suspension from a flow cytometer and analyze data, smooth curves, calculate new parameters and notify of expiration of the system.

Abstract: An aqueous wash composition has been found useful in methods for determination of specific binding ligands. The composition is buffered to a pH of less than or equal to 6 or greater than or equal to 9. It also includes as its essential component at least about 0.1 weight percent of an anionic surfactant which is represented by the formula:[A-SO.sub.3+y ].sup.-(1+y) [X.sup.+m ].sub.nwherein A is a hydrocarbon having a molecular weight of at least about 180, X.sup.+m is hydrogen or a monovalent or divalent cation, m is 1 or 2, is 0 or 1, and n is 1 or 2 provided that m and n are not both 2. Optionally and preferably, the wash composition also includes a nonimmunoreactive protein. This wash composition is particularly useful in methods for determination of microorganisms associated with periodontal diseases. Such methods can be of a variety of formats, but immunometric assays are particularly useful. The wash composition can be included as part of a diagnostic test kit.

Abstract: A method for rapidly lysing liposomes having transition temperatures in the range of 35.degree. to 65.degree. C. is provided. Such liposomes are treated with a surfactant including ##STR1## wherein x represents an average of 9 or 12. The method is applicable to fluorescence immunoassay procedures.

Abstract: Hydroxy coumarin ester enzyme substrates can be stored in a strong base at pH above 11 to stabilize the substrate against premature hydrolysis of the ester bond and to reduce the revel of contaminating hydroxy coumarin. When diluted in buffer at pH below 11 shortly before use in an enzyme assay, the substrate solution provides low background fluorescence.

Abstract: A sorption analyzer for performing surface measurement analysis on sample material. The sorption analyzer calibrates the instrument and the sample cell using the adsorbate gas.

Abstract: Methods for preserving platelets at temperatures of less than about 15.degree.C. with retention of hemostatic activity are provided. The method uses a first agent for inhibiting actin filament severing and a second agent for inhibiting actin polymerization. Contacting the platelets with the first and second agents prior to exposure to cold temperature prevents cold-induced platelet activation.

Abstract: The invention relates to new optically active amino acid derivatives of the general formula (I) ##STR1## in which n, R, R.sub.1, R.sub.2, R.sub.3, X and A have the meaning given in the description, which amino acid derivatives contain sulphoxide or sulphone groups, to two basic synthetic routes for the preparation from sulphur-containing amino acids, to the polymerization of these monomers and to the use of the polymers as optically active adsorbents for chromatographic resolution of racemates to give the enantiomers.

Abstract: An improved calibration method for calibrating the measured value of an analyte in a liquid sample by referring to a calibration curve drawn by plotting the interrelation between the calibration values of n (n is an integer of not less than 2) calibrators containing different contents of the analyte and the measured values of the analyte contained in respective calibrators.

Abstract: Compositions, such as liquid therapeutic or diagnostic compositions, and methods for their preparation and involving their use. The compositions comprise an effective amount of gelatin from cold water fish skin as a protein base. The indicated gelatin provides many significant advantages and improvements, including for instance its high stabilizing effect on labile organic substrates included in the compositions, and its low temperature gelling properties which provide improved compositions which do not substantially gel during refrigeration. Further representative advantages relate to its behavior as a zwitterion thus reducing or eliminating needs for buffers, and its surprising behavior similar to human serum protein in protein analyses such as the biuret procedure.

Abstract: An endless loop calibration system comprising a sensor cassette having a flow-through passage and at least one sensor to be calibrated, a chamber coupled to the sensor cassette to define an endless loop, a calibration liquid in the endless loop, and a valve element which is employed to prevent the flow of calibration liquid through the endless loop. This valve element, preferably carried by a housing, urges a tube compressor to squeeze a compressible tube against a curved wall surface sufficiently to prevent fluid from flowing in the compressible tube across the zone, and to maintain the at least one sensor in the sensor cassette wet with calibration liquid for long term storage of the calibration system.

Abstract: Assay methods are provided for determining the presence of lithium in high sodium content liquids such as serum, plasma, urine or other sample without deproteinization. The novel compounds are water soluble derivatives of TMC-crownformazans and provide signal enhancement by increased absorbance of the dye-lithium complex over the dye anion.

Abstract: A method for the production of a standard oxide sample for X-ray fluorescence analysis of an impurity element contained in an inorganic compound. The standard oxide sample is produced by accurately weighing a high-purity compound of the type of the main-component element of the inorganic compound, dissolving the weighed compound in an acid, adding an element of the type of the impurity element to be subjected to determination in a prescribed amount to the acid solution, evaporating the resultant solution to dryness, and heating the dry residue of evaporation.

Abstract: A stabilized, aqueous composition containing FK506. FK506 degrades rapidly in most aqueous matrices. The rate of degradation is decreased in the presence of unfixed blood cells or fragments of blood cells from human or animal sources. A number of matrices using blood components are possible. Blood can be used directly or the blood cells can be lysed. The blood is diluted with a solution of an alkali halide.

Abstract: A method of screening for the endometrial cancer cells in a endometrial cell specimen is disclosed. The method involves determining the amount of an endometrial cancer associated antigen relative to the sample amount by immunologically detecting and comparing the levels of the endometrial cancer associated antigen and a substance present in human cells in a substantially constant amount.

Abstract: The present invention provides an aqueous buffer solution and method and solution for hydrating and calibrating a sensor membrane of a fiber-optic catheter useful for measuring an analyte other than chloride in a physiological milieu. The temperature, gaseous atmosphere, and aqueous buffer solution of the sensor component are controlled throughout the calibration process in order to ensure that the device is calibrated in accordance with its intended use. The solution is chemically compatible with the intended use of the device and provides compensation for evaporative loss, contaminants, or changes in the solution occurring during storage especially in plastic containers.

Abstract: Surfaces of polymeric materials are coated with a layer of thermally denatured fibrinogen. The fibrinogen may be treated with thrombin to produce fibrin, and additional fibrinogen and factor XIII added to produce a cross-linked fibrin coating. The resulting coated surface is stable, anti-thrombotic and resistant to platelet adhesion. Polymeric materials coated in this way are useful in constructing vascular grafts and prosthetic devices, and provide test systems useful in the study of thrombogenesis.

Abstract: An analyzer has a reaction disk for holding a plurality of reaction containers and a fluorophotometer for measuring fluorescence stemming from solutions in the containers. Most of the containers contain solid phases attached with antibodies but at least one container does not contain any solid phase. In normal operation of the analyzer, a test sample containing antigens and a latently fluorescent reagent such as an antibody labeled by an enzyme are added to a container containing a solid phase. In this container, a fluorescent substance is created through an enzyme reaction. Light is irradiated on the container and the fluorescence emitted from the fluorescent substance is measured. While measuring test samples, fluorescence stemming from a reference sample, such as quinine sulfate, is measured to produce values for the reference sample by which measured values for the test samples are corrected.

Abstract: A standard whole blood composition is disclosed, which is useful as a pooled human hemostasis reference standard in blood coagulation assays including Activated Clotting Time (ACT), Whole Blood Prothrombin Time (WBPT), Whole Blood Activated Partial Thromboplastin Time (WBAPTT) and Whole Blood Thrombin time (WBTT). Also disclosed are methods for determining the human standardized potency of heparin and protamine.

Abstract: The present invention discloses a DNA marker ladder useful in Southern blot hybridizations. The ladder is made up of pooled DNA restriction endonuclease digests, where each restriction digest contains at least one fragment complementary to a probe and at least one fragment not complementary to the probe. The regions of complementarity between the probe and the complementary fragments are double-stranded segments of the fragments. The ladder is characterized by an approximately even spacing of bands, resulting from choosing fragments having an logarithmic size distribution. Kits incorporating this ladder and a probe or means for making a probe or a probe and a means for labeling a probe are also disclosed.

Abstract: A method of setting up a flow cytometer using microbeads fluorescing at a plurality of wavelengths, control cells for each of said wavelengths, certified blank microbeads. The blank microbeads are run and the PMT voltages are adjusted so that the blank microbeads are on scale on the flow cytometer. The control cells are run and the photomultiplier tube voltages are adjusted so that the single population falls in selected channels. The fluorescent microbeads are run on the flow cytometer and the Target Channels for the flow cytometer are determined.

Abstract: There are essentially three aspects to the present invention. In a first aspect, there is provided solid-phase calibration materials for selectively imparting predetermined inorganic or organic carbon levels to a fluid stream by dissolution, comprising solids that are sparingly and selectively soluble in the fluid stream. In a second aspect, the same materials may be used as standards for calibrating an on-line or off-line carbon analyzer at predetermined TIC and TOC levels in a fluid stream. In a third aspect, there is provided a calibration system that utilizes the standards to impart predetermined levels of selected TIC and TOC levels in a fluid sample stream. In one form of the invention, a process is provided for automatically calibrating analytical instrumentation with respect to total organic carbon and total inorganic carbon.