Abstract: An immunoassay element for quantitatively analyzing a ligand by determining the change in enzymatic activity caused by a reaction between the ligand, a linked product of the ligand and a high molecular weight compound and an enzyme-labelled antibody. The immunoassay element comprises a substrate layer containing a non-diffusible substrate which forms a diffusible material in the presence of the enzyme, and a reagent layer containing a fragmenting enzyme for further fragmenting the non-difussible material. Also provided is a process for quantitatively analyzing a ligand contained in a sample by the use of the immunoassay element.

Abstract: An indirect assay for analyte employs a particle derivatized with a plurality of molecules of one or more compounds to increase assay sensitivity. In an indirect sandwich assay format, at least one of the compounds is a binder for the analyte, and the tracer is comprised of a binder for at least one of the compounds on the particle. In this manner, a plurality of tracer molecules may be indirectly bound to a single analyte molecule which is bound in a complex formed in the assay.

Abstract: Specific binding ligands can be detected with an assay which utilizes an immobilized receptor for the ligand, a reporter enzyme, an inhibitor antibody and an anti-inhibitor antibody. Both antibodies are specific for the reporter enzyme. The inhibitor antibody effectively shuts down the activity of the reporter enzyme when it is complexed thereto. The anti-inhibitor antibody binds to the reporter enzyme, does not affect the enzymatic activity, but prevents the binding of the inhibitor enzyme. This assay provides a direct correlation of the target specific binding ligand to the signal generated without the use of separation or wash steps.

Abstract: A dry immunoassay analytical element, for assaying a ligand, comprising a support bearing:(a) a labeled ligand zone;(b) a spreading zone; and(c) a receptor zone containing a fixed concentration of an immobilized receptor for the ligand and the labeled ligand and the receptor is covalently bonded to polymeric beads having a diameter in the range of 0.1 to 5 .mu.m;characterized in that the element contains a compound containing a vanadium IV (V.sup.+4) ion and the zones can be in the same or separate layers.

Abstract: A method for synthesizing and screening oligonucleotides on a solid substrate. The method provides for the irradiation of a first predefined region of a substrate comprising immobilized nucleotides on its surface, without irradiation of a second predefined region of the substrate. The irradiation step removes a protecting group from the immobilized nucleotides. The substrate is contacted with a first nucleotide to couple the nucleotide to the immobilized nucleotides in the first predefined region without coupling in the second predefined region. At least a part of the first predefined region and at least a part of the second predefined region are subjected to further irradiation. The substrate is contacted with a second nucleotide, which couples to the immobilized nucleotides in at least part of the first and at least part of the second predefined regions. By repeating these steps, an array of diverse oligonucleotides is formed on the substrate.

Abstract: An immunoassay element comprising at least one layer containing a leuco dye coating composition comprising:______________________________________ Dry Weight Component Ratio (Range) ______________________________________ a) Triarylimidazole leuco dye 55-80 b) Antioxidant 7-40 c) Poly[poly(ethylene oxide)-block- 6-20 poly(propylene oxide)] nonionic block copolymer d) Alkylaryloxypoly(alkylene oxide) 1-16 nonionic surfactant ______________________________________

Abstract: The present invention relates to an apparatus for performing a fluoroimmunoassay, the apparatus comprising an excitation light source, a fluorescence detector, an optical fiber for an excitation light from the excitation light source to which an antigen or antibody is bound, and a spectroscope, in which the mentioned antigen or antibody is bound to an outgoing end surface of the optical fiber for the excitation light. In the apparatus the spectroscope is constructed so that it introduces the excitation light emitted from the excitation light source to a incident end surface of the optical fiber for the excitation light and introduces a fluorescence emitted from a fluorescence-labeled antibody or antigen which forms an immunological complex with the antigen or antibody to the fluorescence detector. In the apparatus the outgoing end surface of the optical fiber for the excitation light has a transmittance for the excitation light from the excitation light source.

Abstract: An enzyme-labelled antibody adapted for use in a homogeneous immunoassay is provided. The enzyme-labelled antibody is a conjugate of an enzyme with two or more different monoclonal antibodies, each of the monoclonal antibodies being capable of specifically recognizing and binding to a different epitope of the same antigen. By using the enzyme-labelled antibody in the homogeneous enzyme immunoassay process, an analyte can be quantitatively analyzed at a higher sensitivity through a simple operation. Also provided is a dry immunoassay element comprising an immunological reaction layer containing the enzyme-labelled antibody. By the provision of such an immunoassay element, a further simplified quick analysis of an analyte is realized to give an accurate result.

Abstract: A method and apparatus for preparation of a substrate containing a plurality of sequences. Photoremovable groups are attached to a surface of a substrate. Selected regions of the substrate are exposed to light so as to activate the selected areas. A monomer, also containing a photoremovable group, is provided to the substrate to bind at the selected areas. The process is repeated using a variety of monomers such as amino acids until sequences of a desired length are obtained. Detection methods and apparatus are also disclosed.

Abstract: A target substance is detected by a sandwich immunoassay using fine particle (A) having bound to it a fluorescer and an antibody reacting specifically with the target substance, and a fine particle (B) having bound to it a quencher and an antibody reacting specifically with the target substance, through a different antigenic determinant. Also disclosed is a competitive immunoassay having a fine particle (C) bound to it a fluorescer or a quencher, and an antibody reacting specifically with the target substance, a bound product (D) composed of the remainder of the fluorescer and the quencher, or a known amount of the target substance. Binding of the fluorescer and the quencher to the fine particle (A), (B) or (C) is affected so that the fluorescer and the quencher are covalently bound to a substance adsorbed on the fine particle.

Abstract: Subject matter of the invention is a new method of detecting a substance with hydrolase activity in a sample, characterized in that the sample is brought into contact with an indicator enzyme, which is covalently bound to an insoluble carrier material and can be rendered soluble by the hydrolase activity, in that the cleaved off indicator is separated and in that its enzymatic activity is determined and test means for its implementation.

Abstract: The present invention is directed to a membrane-based immunoassay method for an analyte of interest having at least two sterically separate antigenic sites. The method comprises providing a reactive membrane having a calibration zone and a test zone, wherein the calibration zone is characterized by having a predetermined amount of the analyte of interest immobilized via a first antibody as a first specific binding pair to a solid phase, the immobilized first binding pair being covalently cross-linked such that any remaining binding sites on said first immobilized antibody are substantially incapable of further specifically binding to any additional analyte, but at least some of said analyte is capable of specifically binding to a preselected amount of a labelled second antibody.

Abstract: This invention relates to an improved assay device and assay for detecting or quantitating the presence or absence of a substance in a sample. The device has multiple layers comprising a permeable layer (a) having a capture reagent attached to less than the entire membrane, a selectively permeable layer (b) which does not allow assay reagents to pass through (b) and an absorbent layer (c). Layer (b) is in communication with layers (a) and (c). Layer (b) has at least one hole extending therethrough and the hole or holes are directly below the capture reagent in layer (a). The area of the hole or the combined area of the holes is less than the area covered by the capture reagent. This invention also relates to a method of reducing background color development in an absorbent layer of an assay device.

Abstract: A method and device for forming large arrays of polymers on a substrate (401). According to a preferred aspect of the invention, the substrate is contacted by a channel block (407) having channels (409) therein. Selected reagents are flowed through the channels, the substrate is rotated by a rotating stage (403), and the process is repeated to form arrays of polymers on the substrate. The method may be combined with light-directed methodolgies.

Abstract: An analysis element for the determination of an analyte in a liquid sample, especially for medicinal uses. A carrier layer (2) contains, in a reagent domain (4), a reagent applied in a defined pattern by an ink-jet process. The pattern comprises several sets (A, B, C) of compartments (11-20), the compartments (e.g. 11, 13, 15, 17, 19) of the same set (e.g. A) having the same chemical composition, the compartments (11, 13, 15, 17, 19 or 12, 16, 20) of different sets (A or B) containing different reagents and the compartments of different sets being arranged in alteration so that the compartments containing different reagents are close together but nevertheless spatially separated.

Abstract: A microassay card includes an upper layer containing wells for receiving a liquid sample. A second layer of the card, beneath the first layer, includes a supporting surface bound to a reactive species. A third layer includes a superabsorbent support impregnated with an indicator. Typically, the indicator is a substrate for an enzyme, such as a reduced dye precursor and a source of hydrogen peroxide necessary for the action of the enzyme upon the substrate to cause a spectral change in the absorbent layer. By selecting the structure of the first and second layers, the card can be formatted for a displacement assay or a competitive assay. The microassay card of the present invention is particularly useful for drug testing.

Abstract: Biologically active reagents are prepared from particles of copolymers having polyoxyalkylene side chains, each of which side chains has a molecular weight of at least about 88. The reagents are prepared by covalently attaching biologically active substances, for example antibodies, to the particles, directly or indirectly through reactive groups on the particle surface. These reagents are used to advantage in analytical elements and methods for the detection of specific binding ligands (such as immunological species) and immunoassays, and in purification methods as affinity chromatography reagents. Adsorption of undesirable proteins on the particles of the reagents was considerably reduced because of the specific composition of the particles.

Abstract: The present invention provides a process for the determination of an enzyme from an isoenzyme mixture in a liquid sample by inhibition of the disturbing isoenzymes and determination of the non-inhibited enzyme, wherein the isoenzyme mixture is contacted with one or more substances which are able to inhibit the disturbing isoenzymes, the sample containing the inhibiting substance(s) is transferred to a small-pored reaction medium and the disturbing enzyme is there inhibited and the determination of the non-inhibited enzyme is carried out in the resulting liquid.The present invention also provides a test carrier for carrying out this process.

Abstract: In order to determine an analyte by a heterogeneous immunological test using a first partner of a binding pair which is immobilized on a solid phase in which a sample solution containing the analyte is incubated in the presence of the solid phase with either(1) a first conjugate consisting of (a) the second partner of the above-mentioned binding pair and (b) a first substance capable of specific immunological binding to the analyte or(2) a first conjugate consisting of (a) the second partner of the above-mentioned binding pair and (b) a first substance capable of specific immunological binding to the analyte as well as with a second labelled substance capable of specific immunological binding to the analyte,afterwards the phases are separated, in case (1) the liquid phase is replaced by a further solution containing a second labelled substance capable of binding specifically to the analyte and it is again incubated and subsequently separated, and in both cases the label on the solid phase or in the liquid pha

Abstract: The invention provides for methods and compositions to detect the presence of anti-HLA antibodies, HLA antigen or preformed HLA-containing immune complexes in biological samples. The complement protein Clq is bound to a solid substrate, then mixed with a biological sample containing immune complexes. The immune complexes are preformed, or formed by adding HLA antigens to a biological sample containing antibodies to HLA, or alternatively, by combining a biological sample containing HLA antigens with defined antibodies to HLA. The immune complexes bind to Clq, and are then detected by the addition of a labeled reagent.

Abstract: An immunochromatography which comprises chromatographically moving a sample together with or followed by labelling fine particles in a chromatographic medium having at least one reaction site having immobilized thereat a reagent bindable to a substance to be detected in a sample, to contact the above sample and the labelling fine particles with the above reaction site, and detecting the substance to be detected by use of the phenomenon that when the above substance to be detected is present in the sample the labelling fine particles are specifically bound to the above immobilized reagent via the substance to be detected at the above reaction site, to thereby capture the substance to be detected on the chromatographic medium, characterized in that the above labelling fine particles are sensitized dyed particles obtained by sensitizing, with a material bindable to the above substance to be detected, labelling dyed particles obtained by dyeing latex particles of a synthetic high polymer, said labelling dyed part

Abstract: A method of preparing a dry-type analytical element for immunoassay having at least one water-permeable porous layer and containing a labeled antigen and an antibody to said labeled antigen and to an unlabeled antigen as the components participating in antigen-antibody reaction in said porous layer, which comprises applying or impregnating a first composition containing one of said labeled antigen and said antibody and thereafter applying or impregnating a second composition containing the other of said labeled antigen and said antibody dissolved or suspended in a solvent not dissolving substantially said labeled antigen or said antibody in the first composition onto said porous layer.

Abstract: A device for the rapid qualitative and quantitative determination of the presence of a reactive ligand in a fluid.This device comprises a first reaction zone in which there is an at least temporarily impermeable membrane designed to receive a sample of test fluid and to be associated with at least one labeled reagent; a second reaction zone which is bounded on the one hand by the said membrane and on the other by a second at least temporarily impermeable membrane comprising a solid phase containing a reference reagent; and a third reaction zone which contains means for developing the reaction.A method for the rapid qualitative and quantitative determination of the presence of a reactive ligand in a fluid.Applications to the detection of the presence, in a biological fluid, of antibodies or antigens in particular.

Abstract: A microassay card for a includes an upper layer containing wells for receiving a liquid sample. A second layer of the card, beneath the first layer, includes a supporting surface bound to a reactive species. A third layer includes a superabsorbent support impregnated with an indicator. Typically, the indicator is a substrate for an enzyme, such as a reduced dye precursor and a source of hydrogen peroxide necessary for the action of the enzyme upon the substrate to cause a spectral change in the absorbent layer. By selecting the structure of the first and second layers, the card can be formatted for a displacement assay or a competitive assay. The microassay card of the present invention is particularly useful for drug testing.

Abstract: Biologically active reactive are prepared from particles of copolymers having polyoxyalkylene side chains, each of which side chains has a molecular weight of at least about 88. The reagents are prepared by covalently attaching biologically active substances, for example antibodies, to the particles, directly or indirectly through reactive groups on the particle surface. These reagents are used to advantage in analytical elements and methods for the detection of specific binding ligands (such as immunological species) and immunoassays, and in purification methods as affinity chromatography reagents. Adsorption of undesirable proteins on the particles of the reagents was considerably reduced because of the specific composition of the particles.

Abstract: Enzyme linked immunosorbent assay (ELISA) methods for quantitatively determining the level of PDGF-BB and PDGF-AB, or, PDGF-AA and PDGF-AB present in a human's bodily fluids, tissue extracts, or a fluid contacting humans cells in culture, are disclosed.

Abstract: A method for drying mammalian cells, such as erythrocytes, lymphocytes, leukocytes and platelets onto a solid-phase support for use in solid-phase immunoassays through use of a drying solution and an article for use in immunoassays prepared by such method. The method comprises immobilizing a monolayer of cells onto the solid-phase support by non-covalent binding. This is accomplished by staining the solid-phase support with an organic dye having a net positive charge which permits non-covalent binding of the cells which carry a net negative charge to the solid-phase support. These cells are dried or fixed to the solid-phase support by addition of a drying solution which comprises an aqueous solution of a monosaccharide, disaccharide, trisaccharide or cyclitol and a salt. The preferred monosaccharide is D-(-)glucose and the preferred salt is sodium chloride. The preferred drying solution comprises a 1.0 M solution of dextrose and a 154 mM solution of sodium chloride.

Abstract: A dipping element for immunoassay or quantitative analysis of an immunoreactive analyte is disclosed having a first matrix having a carrier therein containing an immobilized antibody capable of an immunochemical reaction with a sample antigen. The immobilized antibody is not released into the aqueous liquid sample upon contact. The element further comprises a second matrix which contains labelled antigen which does dissolve in the aqueous liquid sample upon contact. On dipping, the marker-labelled antigen reacts with the immobilized antibody in competition with the antigen-antibody reaction between the analyte antigen and the immobilized antibody. if the analyte is an antibody, then the second matrix contains a marker labelled antibody and the first matrix contains an immobilized antigen. Methods for the quantitative analysis of an analyte antigen or antibody are also disclosed.

Abstract: A diagnostic test strip for chemically determining whole blood analytes comprises a support, a porous detection zone membrane affixed to the support, and an overlay membrane affixed to the support and in overlying and continuous contact with the detection zone membrane. The overlay membrane has a crenating agent for the exclusion of whole red blood cells from the pores of the detection zone membrane.

Abstract: An immunoassay method comprising applying an aqueous solution containing the analyte antigen to one end of a multi-zoned test strip device such that the solution moves along the strip by capillary action. The zones are arranged so that the solution (a) first contacts and reconstitutes dry, diffusible labelled component comprising colloidal gold conjugated to an antibody specific for said analyte antigen and then (b) contacts and reconstitutes dry, diffusible biotinylated second antibody specific for said analyte antigen such that a diffusible, dispersed sandwich reaction product forms. The reaction product diffuses along the strip with the solution and into a zone containing capture component consisting of a latex and avidin complex which avidin collects the reaction product by means of reaction with its biotin moiety. Thus, gold particles are collected and concentrated in the detection zone for visual determination.