Abstract: A method of treating particles to be used in immunoassays reduces interference in particle agglutination assays. For particles having covalently bound antibodies and residual NHS-ester or sNHS-ester groups on the surface, the reactive esters are treated with an aqueous mixture containing an amine compound of formula (I): H2N—R—X??(I). The moiety —X is —NH2, —OH, or —CO2CH2CH3; and R is an alkyl group or an alkyl ether group. When —X is —NH2 or —CO2CH2CH3, R contains from 1 to 20 carbon atoms; and when —X is —OH, R contains from 4 to 20 carbon atoms.

Abstract: The present invention provides biologically active linear polypeptides that possess a plurality of biologically active groups, methods employing such peptides to target molecules to cells, and methods employing such peptides for inhibiting the binding of cells to each other.

Abstract: A particle-enhanced assay for determining an analyte in a test sample in which an additive for reducing non-specific particle aggregation is added in an amount to substantially reduce non-specific aggregation.

Abstract: Disclosed is a method for determining the concentration of an analyte in a sample of body fluid. The method involves contacting the body fluid sample with a test strip containing mobile, labeled specific binding partner for the analyte, through which strip the test fluid, analyte and any complex formed by interaction of the analyte and labeled specific binding partner therefore can flow by capillarity. The strip contains at least one zone for capture of the labeled specific binding partner and at least one separate zone for retention of the analyte/labeled specific binding partner complex. By determining the magnitude of the signal from the detectable label in the capture zone(s) and retention zone(s) and determining a final response signal by correlating signals using an algorithm and number of zones chosen in a manner that provides a final response signal best suited for the particular assay, the concentration of the analyte can be determined with greater precision.

Abstract: The present invention relates to a method for the determination of polyvalent metal ions using a sandwich aggregation assay. One or more chelating agents capable of forming at least 2:1 or higher ratio stoichiometry complexes with polyvalent metal ions are attached to a suitable carrier such as latex particles through covalent bonds or by non-covalent interactions, such as hydophobic interactions. Upon complexation with the metal ions, the carriers of the complexing agent aggregate, causing an increase in light absorbance or light scattering which is proportional to the concentration of metal ions in the test sample. The measurement of the light absorbance or light scattering by a suitable instrument, such as a spectrophotometer or nephelometer provides a means for measuring the concentration of metal ions.

Abstract: Methods and test kits are described which provide a reliable, sensitive and selective assessment of periodontal disease activity, peri-implantitis or HIV(+)-infection/AIDS-disease related periodontal diseases. The preferred methods and test kits are constructed to be easy and rapid chair-side tests. The method is based on the preparation and use of monoclonal antibodies which recognize the active mammalian matrix metalloproteinase-S (MMP-8) and is capable of differentiating between said active matrix metalloproteinase-8 and its inactive proform.

Abstract: This invention describes a method for the rapid identification of the presence of microorganisms in a sample. Briefly, in the method of this invention the sample container is divided into a plurality of discrete zones, each of which can be separately monitored for microbial presence. When a sample is placed into this container, detection is simplified as the volume monitored is low (as compared with the sample); since microbial detection is a concentration dependent phenomenon, the speed with which the presence of microbial contamination can be detected is increased.

Abstract: Methods for modulating the rates and dose responses of immunoassays through the incorporation of one or more detergents into the immunoassay reaction are disclosed. The methods are particularly suitable for automated immunoassay formats, especially with formats that use analyte-biotin bidentate reagents. The methods may be used to facilitate the detection of any desired, preselected pharmacological agent.

Abstract: The invention relates to a method for determining analytes, in which a sample of a biological material which possibly contains this analyte is incubated with at least one binding partner which is specific for the analyte and which is immobilized on a particulate carrier material, and the change in turbidity brought about by the analyte is determined.

Abstract: The invention pertains to a method for diagnosing oncological diseases wherein an effective small amount of blood is obtained, such as from a finger, and a solution containing blood plasma or serum is exposed to laser radiation and the values of one or more parameters are determined upon measurements at molecular level. Said parameters are then compared with analogous measured or established parameters of a reference solution to determine whether there are significant variations or similarities which indicate the absence or presence of oncological diseases or a predisposition to same. In a preferred embodiment of the invention, blood plasma or serum is diluted in water up to 25% of the volume and the solution is then exposed to laser radiation in the standard mode.

Abstract: The invention relates to immunoassay reagents that are both sensitive and specific and which require no sample pretreatment. The invention reagents are particularly useful for assaying digoxin concentrations in patient sera. More particularly, the invention relates to methods and kits comprising (A) an immunoreactant immobilized on a support; and, (B) a buffer agent comprising (i) a buffering agent, (ii) sodium chloride, (iii) choline chloride, (iv) a polysaccharide, (v) fatty-acid-free serum albumin, and (vi) a non-specific reaction suppressor of the formula: ##STR1## wherein X is --NH--(CO)--NH--, --NH--(CS)--NH--, or --N.dbd.C.dbd.N--, R.sub.1 and R.sub.2, which may be the same or different, are C.sub.1 -C.sub.5 linear or branched alkyl groups, or R.sub.1 and R.sub.2, together with nitrogen, is ##STR2## or the metho-p-toluenesulfonate salt thereof, Y, which may be the same or different, is any of H, OH and halogen,R.sub.3 is --NR.sub.1 R.sub.2, --NH.sub.

Abstract: In a stained particle analyzing method and apparatus for staining a test sample containing suspended particles, shooting an image of the stained sample, and classifying the particles and computing the density from the shot image of the sample, the sample, which may not be analyzed precisely, is detected before the start of an image analyzing process. Only the sample, which will be analyzed precisely, is stained and subjected to the image analysis. Color information of the sample before the staining is detected and stored. Color information of an image of the sample shot after the staining is compensated based on the color information of the sample detected before the staining. The sort and density of the particles are classified and computed on the basis of the image after the color compensation.

Abstract: Method for the analytical determination of the concentration of a component of a medical sample, in which a reaction of the sample with reagents leads to a time-dependent change S(t) in a measured quantity S and the concentration C correlates according to an evaluation curve C(X) with an input variable X derived from S(t), in which the calibration curve is ambiguous for at least a portion of the possible X values. In order to assign an input variable X to one of the sub-sections and thereby to obtain an unambiguous correlation to a particular concentration C, a training run and an analysis run are performed. In the training run, a discrimination algorithm is performed at least once, in which a discriminator set is generated from measurements of S(t), a score is generated in each case from the latter with a multivariate statistical technique and it is checked whether the scores can be divided into separate subsets, in which the concentrations are correctly assigned to the sub-sections of the calibration curve.

Abstract: A device for detecting substances in a liquid film by measuring chemiluminescence, fluorescence or absorption using techniques such as flow-injection analysis schemes, liquid chromatographies, and gas chromatographies. The device can be used as a micro-volume mixing or reaction substrate for a variety of measurements. The device comprises at least two film supports that are separated by a small gap. One or more applicators are positioned along the gap to supply fluids to the gap. The applicators are positioned near the gap at a spacing that is near the necking length of the fluid supplied by the applicator. A thin, continuous film of the mixture of fluids to be examined is supported in the gap between the film supports. The film extends through the examining chamber and through drop and overflow detection probes. Also disclosed is a mixing or reaction chamber which comprises an enclosable mainframe into which a plurality of applicators are butted near a gap defined between two film supports.

Abstract: A system for analyzing a chemical reaction provides control of the temperature and volume of the reagents to improve the accuracy and precision in quantitative measurements of specific proteins and other immunochemistries in body fluids. The reaction occurs in a cuvette within a nephelometric optics module. A sensor senses the temperatures of reaction buffer liquids as they flow into the cuvette, and a heat exchanging device increases or decreases the temperatures of the buffer liquids. A control circuit responsive to the temperature sensor controls the heat exchanging device to maintain the temperature of the buffer liquids and the cuvette within a selected temperature range. The system may also include a sample pickup station, a sample probe for withdrawing a selected sample from the sample pickup station, a sample preparation station, and transport device for carrying said sample from the sample preparation station to the reaction cuvette.

Abstract: A latex for immobilization of a physiologically active substance is prepared by copolymerizing a monomer mixture comprising:(a) 100 parts by weight of an aromatic vinyl monome4r;(b) 0.01 to 5 parts by weight of a vinyl monomer having a sulfonic acid group;(c) 1 to 20 parts by weight of an .alpha.,.beta.-unsaturated carboxylic acid monomer; and(d) 0.05 to 5 parts by weight of a polyfunctional monomer for internal cross-linking; in water using a water-soluble radical polymerization initiator in the absence of an emulsifying agent. An antigen or antibody or a hapten can be covalently bound to particles of the latex to form a reagent for use in immuno nephelometry.

Abstract: A process for the removal of non-specific turbidities in the carrying out of determinations according to the immuno-assay principle, wherein an inorganic boron compound is added to the sample solution in combination with a buffer system.

Abstract: A system for analyzing a chemical reaction provides control of the temperature and volume of the reagents to improve the accuracy and precision in quantitative measurements of specific proteins and other immunochemistries in body fluids. The reaction occurs in a cuvette within a nephelometric optics module. A sensor senses the temperatures of reaction buffer liquids as they flow into the cuvette, and a heat exchanging device increases or decreases the temperatures of the buffer liquids. A control circuit responsive to the temperature sensor controls the heat exchanging device to maintain the temperature of the buffer liquids and the cuvette within a selected temperature range. The system may also include a sample pickup station, a sample probe for withdrawing a selected sample from the sample pickup station, a sample preparation station, and a sample transport for carrying said sample from the sample preparation station to the reaction cuvette.

Abstract: A scatter signal is produced from light scattered by a precipitate formed by a chemical reaction and non-specific scatter sources. A blanking signal is produced from light scattered only by the non-specific scatter sources that contribute to the scatter signal, and the blanking signal is subtracted from the scatter signal to dynamically produce a signal indicative of the difference between the scatter signals to reduce the effects of non-specific scattering sources in determining the rate of change of the light scattered by the precipitate. One of the scatter signals may be stored and then combined with the other, or the signals may be measured simultaneously and then combined.

Abstract: A windowless flow cell for detecting substances in a flowing fluid stream by chemiluminescence, fluorescence or absorption in flow injection analysis schemes, liquid chromatographs, or gas chromatographs is described. Furthermore, the mixing characteristics of the invention suggest its use as a micro-volume mixing chamber for a variety of experiments.A windowless flow cell comprising an upper body plate, upper wire spacer, mid-body plate, lower body spacer plate, and lower body plate interconnected by anchor bolts is described. Cell wires are attached to the upper body plate and the lower body plate. A primary reagent port through the upper body plate, with secondary reagent port and tertiary reagent port through the mid-body plate provide the fluids to be mixed. A thin film of the mixture of fluids to be examined flows down the cell wires through the examining chamber and through the drop detector and overflow detector prior to exiting the drain port by way of a low vacuum source.

Abstract: A system for detecting analytes in air or aqueous systems includes a permeation absorption preconcentrator sampler for the analytes and analyte detectors. The preconcentrator has an inner fluid-permeable container into which a charge of analyte-sorbing liquid is intermittently injected, and a fluid-impermeable outer container. The sample is passed through the outer container and around the inner container for trapping and preconcentrating the analyte in the sorbing liquid. The analyte can be detected photometrically by injecting with the sorbing material a reagent which reacts with the analyte to produce a characteristic color or fluorescence which is detected by illuminating the contents of the inner container with a light source and measuring the absorbed or emitted light, or by producing a characteristic chemiluminescence which can be detected by a suitable light sensor. The analyte can also be detected amperometrically.

Abstract: A method and apparatus for use in quantifying, in a whole blood sample in which the red cells are lysed, a component which will react with a reagent to form an antigen-antibody complex, the method comprising mixing the sample with the reagent to obtain the complex, exposing the sample to a source of radiation and measuring the intensity of radiation scattered through a given angle by the complex, and the apparatus including a container for receiving the sample which has been treated with the reagent to the component, the container being transparent to radiation having a wavelength falling within a given band width, typically 460-530 nm. A source of radiation within this band width is provided together with a device for detecting the intensity of radiation scattered through a given angle by the sample.

Abstract: The peak verify time for kinetic nephelometric measurements of reactions between antigens and antibodies is adjusted as a function of the magnitude of the peak rate order to reduce the time required for peak verification. The scatter signal is zeroed following the end of the peak verification period and the reaction is tested for antigen excess. Reactions during the antigen excess check having rates that exceed a threshold value are accepted as being valid, and no additional measurements are made for such samples. Reactions during the antigen excess check having rates that are less than the threshold value are rejected as being in antigen excess. Samples found to be in antigen excess are diluted and then reanalyzed.

Abstract: An instrument for measuring coagulation parameters is provided in which plasma and at least one reagent are mixed by spinning in a cuvette with transparent windows and in which measurement is then made of scatter by the mixture of the energy of a light beam sent into the mixture.Upon spin, the plasma components and reagent are displaced into the chamber, thus determining the initiation of the presence of the mixture in which the clot forms, and a photodetecting unit senses the change in the energy of the scattered light, caused by clot formation.

Abstract: A photometric method and apparatus for measuring agglutination in a biological agglutination reaction system test sample using a laser beam source and at least one photodetector for detecting light scattered by the test sample. The method includes the following steps: (1) arranging the at least one photodetector so as to be capable of detecting scattered light from the test sample at a scatter angle of 30 to 60 with respect to a laser beam directed at the test sample from the laser beam source; (2) irradiating the test sample with the laser beam from the laser beam source; (3) selectively detecting the intensity of scattered light from the test sample at the scatter angle of 30 to 60 using the at least one photodetector which provides an output indicative thereof; and (4) determining the first derivative of the output of the at least one photodetector with respect to time and obtaining the maximum value thereof.

Abstract: A method for the quantitative determination of lithium in a liquid test sample employing turbidimetric or nephelometric techniques to measure the maximum rate of change in the optical density of a reaction mixture containing precipitated lithium. The lithium is precipitated by a lithium precipitating reagent to result in dispersed, suspended particles, and the maximum rate of change in optical density determined to provide a linear dose response which can be quantitatively correlated to the amount of lithium present in the test sample.

Abstract: A method is disclosed for determining the presence of a member of a specific binding pair ("sbp member") consisting of ligand and its homologous receptor in a sample suspected of containing the sbp member. The method comprises combining in an assay medium the sample and an opaque particle capable of agglutinating in the presence of the sbp member. The opaque particle has a particle size of from about 0.2 to 5.0 microns. Next, the assay medium is irradiated with light having a wavelength of from about 350 to 2000 nm, and the optical density of the assay medium is measured. A change in optical density indicates the presence of the sbp member in the sample. The method has particular application in the determination of an antibody in a sample, particularly an autoantibody, such as, for example, rheumatoid factor.

Abstract: An improved method and reagents are disclosed for determining a ligand in an assay solution containing the ligand, a reagent system and a luminescent compounds, wherein the intensity of the light emitted by the assay solution is related to the change in the transmittive properties of the assay solution produced by the interaction of the ligand to be determined and a reagent system capable of producing a change in the transmittive properties of the assay solution in the presence of the ligand.

Abstract: Apparatus and method for providing an optical detection of a binding reaction between a ligand and an antiligand, including, a pattern formed by a spatial array of microscopic dimensions of antiligand material, ligand material interacting with the antiligand material to produce a binding reaction between the ligand and the antiligand in the pattern, a source of optical radiation including energy at at least one wavelength directed to the pattern at a particular incidence angle to produce scattering of the energy from the pattern in accordance with the binding reaction and with a strong scattering intensity at one or more Bragg scattering angles, and at least one optical detector located relative to the pattern and aligned with a Bragg scattering angle to detect the strong scattering intensity at the Bragg scattering angle to produce a signal representative of the binding reaction.

Abstract: Apparatus and method for providing an optical detection of a binding reaction between a ligand and an antiligand, including, a pattern formed by a spatial array of microscopic dimensions of antiligand material, ligand material interacting with the antiligand material to produce a binding reaction between the ligand and the antiligand in the pattern, a source of optical radiation including energy at at least one wavelength directed to the pattern at a particular incidence angle to produce scattering of the energy from the pattern in accordance with the binding reaction and with a strong scattering intensity at one or more Bragg scattering angles, and at least one optical detector located relative to the pattern and aligned with a Bragg scattering angle to detect the strong scattering intensity at the Bragg scattering angle to produce a signal representative of the binding reaction.