Abstract: This invention relates to methods for reducing background fluorescence in cell detection and measurement systems. In accordance with one aspect of the invention, cell-impermeant chemical agents are used to modify the fluorescent probes that reside outside the cells to be detected. The chemical agents can chemically modify one or more functional groups in the probes, thereby reducing or eliminating the fluorescence of the probes. In accordance with another aspect of the invention, Acid Black 48 is used to reduce background fluorescence produced by fluorescent probes such as SYTO 62.

Abstract: Methods and reagents are provided for determining endocytosis, using a cell expressing an externally polypeptide labeled cell membrane receptor, and as a reagent an antibody to said label conjugated to a fragment of an enzyme fragment complementation pair. Compounds are tested for their effect on endocytosis by complexing the reagent with said cells, adding the test compound at any time in relation to the complexing, allowing any endocytosis to occur, proteolytically degrading external enzyme fragment, adding protease inhibitor and the complementary member of the enzyme fragment complementation pair and substrate. The product provides a detectable signal related to the amount of endocytosis that occurred. The method is readily automated as all steps can occur in a single vessel without separations and washings.

Abstract: The present invention provides methods for determining a ratio of an amount of a glycated form of a protein to a total amount of the protein in a sample containing the glycated protein, the glycosylated protein, or the glycoprotein. The method incorporates lateral flow test strip or vertical flow test strip devices having negatively charged carboxyl or carboxylate groups and hydroxyboryl groups immobilized and interspersed on a solid support matrix. The solid support matrix may include derivatives of cellulose (e.g., carboxy cellulose) derivatized with carboxylic acid (e.g., carboxylate, carboxyl) groups and hydroxyboryl compounds including phenylboronic acid (e.g., phenylborate), aminophenylboronic acid, boric acid (e.g., borate), or other boronic acid (e.g., boronate) compounds. The present invention is usefi.il for monitoring glycation or glycosylation of hemoglobin or albumin for monitoring glycemic control (e.g., glycemia in diabetes).

Abstract: This invention relates to a biospecific assay method, in which microparticles coated with the bioaffinity reactant A binding the analyte to be assayed; the sample to be analyzed, and the labelled bioaffinity reactant B are mixed. After the binding reaction the signal strength from the labelled bioaffinity reactant B bound to the microparticles is quantitated for the determination of the concentration of the analyte in the sample. According to the invention, such an amount of sample and microparticles is used in the assay that after binding of the analyte of the sample to the said amount of microparticles, each individual microparticle will emit such a signal strength as to allow the measurement of the analyte concentration over the whole range of typical analyte concentrations, and the signal strength from each microparticle is measured separately.

Abstract: The invention provides in vitro methods of detection using human antibodies. The methods are particularly useful for analyzing human samples containing HAMA or heterophilic antibodies. A human antibody can bind to an analyte in such samples without binding to HAMA or heterophilic antibodies present in the samples. The methods can be effected using a sandwich format among others.

Abstract: A method of preparing a sample of muscle tissue and of assaying the prepared sample to determine the presence of prions in the sample is disclosed. The muscle tissue is homogenized and mixed with a complexing agent which forms a complex with a higher specific gravity than PrPSc, the complexing agent or other components of the homogenate. Gravity is then used (e.g. ultra centrifugation) to concentrate the complex and the concentrate is assayed to detect prions. The muscle tissue is preferably extracted from a muscle or group of muscles such as hind limb muscle which have a higher or more preferably the highest concentration of prions as compared to other muscle in the mammal.

Abstract: A sample is prepared from blood in a manner which makes it possible to further analyze proteins in the sample, e.g. to detect prions in the sample. Blood is extracted, allowed to clot and subjected to separation processing (e.g. centrifugation) to obtain serum. The serum is treated with a complexing agent which agent binds prions in the sample forming an agent/protein complex which makes it possible to concentrate the complex. Concentration of the complex results in a sample which can be successfully analyzed, e.g. assayed using a range of different types of assay methodologies for detecting prions.

Abstract: A method for preventing or inhibiting non-specific binding reactions between a detection reagent and an antigen in an immunological assay is described. The method involves using tetrameric antibody complexes that can bind to the antigen and are comprised of two monoclonal antibodies of a first animal species linked to two monoclonal antibodies of a second animal species that can bind the antibodies of the first animal species. Preferably, the antigen is an Fc Receptor and the method reduces the binding of a detection antibody with Fc receptors present on the surface of many cells.

Abstract: The present invention provides an improved system for detecting the presence or level of an analyte in a sample. In “competition-like” assays of the present invention, a sample including an analyte is mixed with a second ligand to which the analyte binds, and the mixture is exposed to a solid phase containing a first ligand that can compete with the analyte for binding to the second ligand. According to the present invention, the time of exposure of the mixture to the solid phase is limited so that substantially no dissociation of analyte/second ligand complex occurs. The competition-like assays of the present invention are preferably performed with a solid phase containing a substantial excess of first ligand. In “sandwich-type” assays of the present invention, a sample including an analyte is contacted with a solid phase including a first ligand that binds the analyte and, simultaneously or subsequently, is contacted with a second ligand that binds the analyte (or the analyte/first ligand complex).

Abstract: The invention relates to an anti HIV 1 vaccine comprising the entire or part of the Tat HIV 1 protein, in addition to the identification of said protein in individuals affected by HIV. The Tat protein is a protein of the HIV 1 Oyi variant.

Abstract: A monoclonal antibody-based Dot-ELISA assay for the rapid detection of animal viruses such as avian influenza virus. The assay includes applying a specimen suspected of containing an animal virus on a porous membrane and treating the specimen with a solution of citric acid or lactic acid and a solution containing a mucolytic agent and a detergent. The treated specimen is then contacted with a primary monoclonal antibody for detecting the virus. If present, the primary moncolonal antibody bind with an antigen of the animal virus specimen. The specimen is contacted with an anti-monoclonal antibody conjugate (secondary antibody) and incubated to facilitate binding of the antigen-bound monoclonal antibody to the conjugate. The bound conjugate and antigen-bound monoclonal antibody is contacted with a coloring reagent to allow visual detection of the presence of the animal virus in the specimen.

Abstract: Assays are provided for rapid detection, with high specificity of the pathogenic form of prion protein responsible for neurodegenerative diseases affecting humans and animals, such as transmissible spongiform encephalopathy in bovine, sheep, and cats. Also provided are assays for testing animal feedstock, such as animal feed, for the presence or concentration of pathogenic prion protein. Results are available in from about 0.5 to about 20 minutes and preferably within from about 5 to about 10 minutes. The assays employ proteinase-K to remove normal prion protein from a biological sample, so that the sample may be analyzed by immunochromatography to determine the presence and concentration of pathogenic prion protein. Because the proteinase-K is immobilized on a solid support for in situ removal of interfering components, the present invention obviates the need for subsequent extraction of the desired analyte.

Abstract: The present invention employs a dissolved activated polyethylene glycol (aPEG) or related molecule that has been passed through a filtration means for the substantial reduction of bioburden or endotoxin levels in the aPEG solution. The resulting filtered aPEG solution can be used for the preparation of a PEGylated hemoglobin solution containing substantially reduced levels of bioburden or endotoxin.

Abstract: The invention relates to analytical methods in which the partition of a labeled substance between a liquid and a solid phase is determined. The assays include solid-phase reagents which can be particulate or monolithic such as, for example, a coated tube. Assays of this type are known per se to the person skilled in the art and include immunoassays and immunometric assays.

Abstract: The present invention relates to a method for monitoring the effect of in vivo administration of Cathepsin S inhibitors by measuring accumulation of an intermediate degradation product of invariant chain (Ii), in particular the p10 Ii fragment, in blood of dosed subjects.

Abstract: This invention provides a novel device and method for preparing cytology slides. The device comprises a book-like form including an absorbent material and filter attached to the inside surface of a front cover and a cytology slide removeably attached to an inside surface of a back cover. A sample is removed from the body of a patient, placed in a liquid-based solution, and then on the filter. When the book-like form is closed, the sample is effectively transferred to the slide. The device can be modified so that a plurality of slides are prepared at the same time.

Abstract: The invention concerns a method for the detection of an analyte in a sample using analyte-specific conjugates which have at least one heterologous group for an analyte-independent binding to a control zone. The present invention additionally provides new conjugates and reagent kits.

Abstract: The invention provides methods and compositions for exploiting the discovery that members of the small integrin-binding ligand, n-linked glycoproteins family termed SIBLINGS bind to complement Factor H, and moreover that SIBLINGS proteins, such as BSP, exist in relatively acidic forms. The methods provided can be used to detect SIBLINGS proteins in samples from subjects that are suspected of having tumors or abnormal bone turnover. The invention also provides methods of using SIBLINGS proteins to protect cells from complement mediated lysis. Finally, the discovery allows for the creation of specific binding agents that facilitate the detection of SIBLINGS proteins when they are associated with Factor H.

Abstract: Antibodies and methods are described for the detection and quantitation of cardiac specific troponin I in samples. Cardiac-specific troponin isoforms exist in various forms in the blood, including free and complexed forms. By selecting antibodies that are insensitive and/or sensitive to these various forms, the present invention can provide immunoassays that more accurately reflect the clinical state of an individual. These described antibodies and methods can be used for providing indicators of myocardial infarction and other cardiac pathologies.

Abstract: The instant invention describes an analytical assay to accurately measure an analyte in the presence of an interfering substance.

Abstract: Water-soluble polymer is added to the liquid phase in a heterogeneous a immunoassay of serum, the polymer having monomers in common with monomers of the solid phase surface. This reduces non-specific binding of IgG's from the serum to the solid phase surface and thereby reduces the occurrence of false positive readings in the immunoassay.

Abstract: Improved methods, reagents, and kits for quantitation of HLA-DR and/or CD11b expression on peripheral blood cells are presented. Inclusion of a lysosomotropic amine, such as chloroquine, during staining stabilizes HLA-DR and CD11b expression. Use of a novel anti-CD14 conjugate, anti-CD14-PerCP/CY5.5, permits the ready discrimination of monocytes. The improved methods, reagents, and kits may be used to assess immune competence, and to direct and monitor immunostimulatory therapies in septic patients exhibiting monocyte deactivation.

Abstract: Assay systems and specialized antibodies for the detection and quantitation of troponin I and troponin T in body fluids as an indicator of myocardial infarction. Since troponin I and T exist in various conformations in the blood, the ratios of the monomeric troponin I an T and the binary and ternary complexes, as well as which form of troponin present in the blood, may be related to the metabolic state of the heart. Disclosed is a system to determine the presence of a troponin form or a group of troponin forms in a sample of whole blood, serum or plasma. Disclosed is a stabilized composition of troponin; the stabilized composition can comprise a stabilized composition of troponin I, wherein the troponin I is oxidized, the troponin I can be unbound or the troponin I can be in a complex. Disclosed is a method for improving the recovery of troponin I or T from a surface used in immunoassays.

Abstract: The present invention relates to a specific C-peptide assay method which can eliminate all interference due to proinsulin and its intermediates, in particular des-31,32-proinsulin and/or des-64,65-proinsulin. It also relates to antibodies for carrying out this assay.

Abstract: Provided is a microarray substrate. The microarray substrate includes a patterned photoresist film having one or more spot regions therein. The photoresist film can be detached from the substrate.

Abstract: A method for classifying and counting leukocytes comprises the steps of: (1) adding to a hematological sample the following fluorescence-labeled antibodies labeled with fluorescent dyes which emit fluorescences distinguishable from each other; (a) a first fluorescence-labeled antibody (1st antibody) which bonds specifically to leukocytes, (b) a second fluorescence-labeled antibody (2nd antibody) which bonds to at least one kind of neutrophilic cells, and (c) a third fluorescence-labeled antibody (3rd antibody) which bonds to at least one kind of immature granulocytic cells, in order to stain leukocytic cells in the sample, and removing erythrocytes from the sample; (2) analyzing the resulting sample using a flow cytometer to measure at least one scattered light signal and three separate fluorescence signals; (3) defining a group of granulocytic cells on the basis of intensity of the scattered light and intensity of fluorescence from the 1st antibody; (4) defining neutrophilic cells in the defined group of gra

Abstract: The present invention provides an immunoassay for specifically measuring with high sensitivity PIVKA-II in serum or plasma through antigen-antibody reaction by adding an animal serum containing thrombin and/or an antibody reacting with human fibrin-like related substances to the reagents. The immunoassay of the invention comprises the steps of adding thrombin and/or an antibody reacting with human fibrin-like related substances to the reagents, and measuring PIVKA-II in serum or plasma.

Abstract: This invention provides a novel device and method for preparing cytology slides. The device comprises a book-like form including an absorbent material and filter attached to the inside surface of a front cover and a cytology slide removeably attached to an inside surface of a back cover. A sample is removed from the body of a patient, placed in a liquid-based solution, and then on the filter. When the book-like form is closed, the sample is effectively transferred to the slide.

Abstract: The present invention relates to a method for releasing a ligand from a complex of the ligand with an endogenous protein using a releasing agent.

Abstract: In order to accurately and reliably quantitate HLE on the plasma membranes of the lymphocytes and mononuclear phagocytes, a test sample containing the lymphocytes and mononuclear phagocytes is initially treated with a first antiserum specific for CD4 receptors on the plasma membrane or with a second antiserum specific for chemokine receptors on the plasma membrane. Once the CD4 or chemokine receptors have been rendered non-reactive (competitive) relative to the HLE receptors (also “binding sites”) on the plasma membrane, the test sample is contacted with an immunoreagent specific for interaction with one or more of the HLE receptors on the plasma membranes of the lymphocytes and mononuclear phagocytes. The immunoreagent forms a complex with the HLE binding sites and produces a characteristic physical change in the lymphocytes and mononuclear phagocytes that can be monitored by any one of a number of standard techniques, (e.g., confocal laser scanning microscopy and flow cytometry).

Abstract: An immunoassay for detecting an antigen in a sample, by: (a) sequentially contacting the sample with (i) a first antibody which is capable of specifically binding to a first binding site on the antigen, and then (ii) a second antibody which is capable of specifically binding to a second binding site on the antigen, thereby forming, when the antigen is present in the sample, an agglutinate comprising the first antibody, the antigen, and the second antibody; followed by (b) optically measuring the amount of the agglutinate.

Abstract: Reagents and the use of the reagents in a microparticle light scattering agglutination assay are disclosed. The reagents comprise a mixture of particles having relatively stronger light scattering properties and particles having relatively weak light scattering properties with respect to one another. The particles having strong light scattering properties carry a binding partner of high reactivity with the analyte. The particles having weak light scattering properties carry a binding partner of low reactivity with the analyte.

Abstract: Disclosed is an improvement in the analysis for an analyte in a urine test sample in which the urine is contacted with a labeled antibody specific to the analyte and the concentration of the analyte is determined by measuring the response from the label. The improvement involves maintaining the concentration of urea in the test sample above the threshold value which value is the concentration of urea at which increases in the urea concentration do not affect the accuracy of the assay such as by interfering with the binding between the analyte and the labeled antibody.

Abstract: The present invention provides methods of purification of Hepatitis A Virus from the supernatant of an infected cell culture and production of a preparation of purified HAV antigen. The present invention is also directed to an HAV vaccine composition comprising a preparation consisting of purified mature HAV particles in an amount sufficient to induce a protective immune response in a mammal.

Abstract: An analytical test device useful for example in pregnancy testing, comprises a hollow casing (500) constructed of moisture-impervious solid material, such as; plastics materials, containing a dry porous carrier (510) which communicates indirectly with the exterior of the casing via a bibulous sample receiving member (506) which protrudes from the casing such that a liquid test sample can be applied to the receiving member and permeate therefrom to the porous carrier, the carrier containing in a first zone a labelled specific binding reagent is freely mobile within the porous carrier when in the moist state, and in a second zone spatially distinct from the first zone unlabelled specific binding reagent for the same analyte which unlabelled reagent is permanently immobilised on the carrier material and is therefore not mobile in the moist state, the two zones being arranged such that liquid sample applied to the porous carrier can permeate via the first zone into the second zone, and the device incorporating me

Abstract: A solid phase with at least one test area is described which contains reagents for the detection of at least one analyte in a sample, wherein the solid phase additionally comprises at least one control area for the detection of interfering reactions.

Abstract: The invention concerns a method for purifying PrPres from a biological sample to be used for qualitative and/or quantitative determination of the PrPres in said sample. The method essentially consists in: (1) incubating, during 30 seconds to 2 hours, at a temperature less than 80° C.

Abstract: The present disclosure relates to a method for determining cholesterol in low density lipoprotein comprising the steps of (a) measuring total cholesterol level in a sample containing at least high density lipoprotein, low density lipoprotein, very low density lipoprotein and chylomicron, and (b) measuring cholesterol levels in the high density lipoprotein, very low density lipoprotein and chylomicron in the sample, wherein the cholesterol level in the low density lipoprotein is determined by subtracting a value obtained in the step (b) from a value obtained in the step (a). The present invention enables concurrent determination of cholesterol level in low density lipoprotein and total cholesterol level, facilitating acquisition of two types of biological information at a time.

Abstract: Cyanide-free reagents for the determination of hemoglobin and leukocytes present in a blood sample comprise an aqueous solutions of at least one quaternary ammonium salt, preferably selected from the group of alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts or alkylpyridium salts consisting of tetradecyltrimethyl ammonium bromide (TTAB), dodecyltrimethyl ammonium chloride, cetyltrimethyl ammonium bromide, hexadecyltrimethyl ammonium bromide and benzalkonium chlorides, and hydroxylamine salts, especially hydrochloride, sulfate and phosphates and other acid salts. The method involves mixing the reagent with a diluent-diluted blood sample, presenting it to an absorbance spectrophotometer and measuring the resulting optical density as an indicator of hemoglobin concentration. This cyanide-free reagent could be used solely for hemoglobin determinations, or, it can also be used in leukocyte counting and sizing using hematology instrumentation.

Abstract: The invention relates to a new dipstick assay for detecting and quantifying the content of an target analyte in a sample. The assay is particularly useful for example in the diagnosis and monitoring of alcoholism by the detection of asialo transferrin or carbohydrate free transferrin (CFT). Thus, provided is a dipstick for determining the content of a target analyte variant in a mixture of analyte variants in a sample, comprising: a) a sample application zone, b) a screening zone having an immobilised binding ligand having a binding affinity for a non-target analyte variant or varinats, c) a conjugate zone comprising a detector reagent, d) a reading zone for detection of said analyte.

Abstract: The present invention relates to an improved immunoassay device for confirming the validity of a test result showing either the presence or absence of an analyte in a patient sample. In the improved device, control reagents are provided in the device which directly mimic the reaction of the sample analyte with the test reagents of the device. The device thus allows the user to verify the efficacy of the test reagents at all stages of interaction with the sample analyte.

Abstract: The invention provides methods of diagnosis using human antibodies. The methods are particularly useful for analyzing human samples containing HAMA or heterophilic antibodies. A human antibody can bind to an analyte in such samples without binding to HAMA or heterophilic antibodies present in the sample. The methods can be effected using a sandwhich format among others.

Abstract: A chromatography assay device and method for use with whole blood samples utilizing a red blood cell separating agent to aggregate red blood cells and permit plasma or serum to flow by capillary action and a neutralizing agent to neutralize any effects the red blood cell separating agent may have on the device and method.

Abstract: The present invention provides an improved system for detecting the presence or level of an analyte in a sample. In “competition-like” assays of the present invention, a sample including an analyte is mixed with a second ligand to which the analyte binds, and the mixture is exposed to a solid phase containing a first ligand that can compete with the analyte for binding to the second ligand. According to the present invention, the time of exposure of the mixture to the solid phase is limited so that substantially no dissociation of analyte/second ligand complex occurs. The competition-like assays of the present invention are preferably performed with a solid phase containing a substantial excess of first ligand.

Abstract: A washing solution for solid-phase immunometric methods which contains stabilizers for the labeling system, and the use thereof

Abstract: A reagent is suitable for measuring the concentration of an analyte in a hemoglobin-containing biological fluid, such as whole blood. The reagent comprises a flavin-dependent enzyme that has specificity for the analyte, a flavin cofactor if, and only if, a flavin is not bound to the enzyme, a tetrazolium dye precursor, an electron transfer agent, and a nitrite salt. The reagent causes dye formation that is a measure of the analyte concentration. The nitrite salt suppresses interfering dye formation caused non-enzymatically by the hemoglobin. Preferably, the reagent is used in a dry strip for measuring glucose in whole blood.

Abstract: An immunochemical method for the determination of antibodies which are specific for an antigen and are of one of the immunoglobulin classes: A, M, D or E in a fluid, with this fluid being contacted with a solid phase to which the antibodies against this immunoglobulin class, or a fragment of an antibody of this type, are bound, which results in the immunoglobulin of this class being bound to this solid phase, and this solid phase being contacted with the antigen, which carries a labeling means where appropriate, and with a labeled antibody or a labeled fragment of an antibody against the antigen if the antigen is unlabeled and determination, from the amount of labeling means which is bound to the solid phase, of the amount of these antibodies which are specific for an antigen and are one of the immunoglobulin classes, which comprises the solid phase being simultaneously in contact with the fluid containing the antibody which is to be determined and with the antigen, which is labeled where appropriate, there b

Abstract: The present invention relates to procedures for the detection or for the determination of solid phase-associated factors, which are multiply associated with the same solid phase. According to the invention, the sample is brought into contact with a transmitter particle, on which at least one ligand having binding affinity for a solid phase-associated factor and a transmitter are immobilized, and a receiver particle, on which at least one ligand having binding affinity for said solid phase-associated factor and a receiver is immobilized, and then the signal is determined which results when transmitter and receiver are brought sufficiently close to one another. In particular, the invention relates to the detection of cell surface receptors which can be used for the typing of cells or for the determination of cell activation states. It is thus possible to replace the hitherto widely customary flow cytometry by a more simple procedure.

Abstract: A method to facilitate recovery troponin I and/or troponin T from a sample comprising addition of troponin C to the sample or to a surface from which the troponin I and/or troponin T are recovered.

Abstract: The present invention relates to improved specific binding assay devices comprising a chromatographic medium including a reaction site at which a specific binding reagent is immobilized, a sample application well located adjacent to the chromatographic medium and offset upstream from the reaction site, and liquid absorption blotter offset downstream from the reaction site.