Abstract: Methods for attaching one component of a ligand-anti-ligand pair onto a solid phase surface. The component may be attached to a photoactivatable cross-linker capable of coupling the component to a colloidal medium coating the surface or alternatively, the component may be coupled to a bead and held in place against the surface by an overlay of the colloidal media having voids and spaces smaller than the diameter of the particle but large enough to permit diffusion of the other of the ligand-anti-ligand pair to be detected.

Abstract: An immunoassay procedure utilizing a formazan-labeled primary antibody to detect the presence of an antigen is disclosed. The formazan-labeled antibody is dissolved in a test fluid suspected to containing the antigen. A dipstick having a first section on which primary antibodies are bonded and a second section free of primary antibodies and antigens and blocked to prevent bonding of primary antibodies and antigens is immersed in the test fluid and removed after a select period of time. A difference in color between the first and second sections indicate the presence of the antigen.

Abstract: A composition of a polysaccharide with a detectable material appended thereto and a 1,3-dione having a methylene group between the two carbonyls of the 1,3-dione, which methylene group has at least one ionizable hydrogen, provides accurate results in assays of hydrolyzing enzymes such as amylase. The composition can be incorporated in the reagent zone of a dry test element having a reagent zone and a registration zone.

Abstract: In its broadest aspect, the present invention provides a method of assaying a ligand in a sample which comprises contacting the sample with a predetermined quantity of a specific binding partner to the ligand, said specific binding partner being immobilized on the effective gate electrode of a field effect transistor, and determining whether (and, if desired, the extent to which) an appropriate transistor characteristic is changed as a result of complex formation between the ligand and the specific binding partner.

Abstract: The present invention discloses a device and a process for quantitation of Toxoplasma gondii and Treponema pallidum antibody titer in a biological sample by immunofluorescent photometric microscopy.

Abstract: A method for detecting and/or determining an agglomerate formed by the reaction between a specific binding agent and the corresponding acceptor substance according to the general methodology of blot overlay assays by using colloidal metal particles labelled components which may be visualized as a coloured signal at the surface of the blotting medium characteristric for the colloidal metal particles used or quantitatively determined following art-known spectrophotometric procedures such as densitometry.

Abstract: A system and method is disclosed for the rapid detection and (or) purification of analytes in a sample. The system makes use of a fluid receptacle containing a capture reagent and a manifold having two ports. A sample containing an analyte disposed within the fluid receptacle is subjected to a capture reagent and processed by inserting the open end of the receptacle in one port. Vacuum, gas, reagents, and wash fluids are then applied to the second port to effect rapid interaction between the capture reagent and analyte, efficient washing of the capture reagent and detection and/or collection of the analyte.The system and method provide a rapid safe, uncomplicated means of automating processes based on affinity complexation principles. Encompassed within this category of processes are immunoassays, nucleic acid hybridization tests and affinity separations.

Abstract: An automatic analysis apparatus is disclosed which provides for various analytical operations in clinical diagnosis and experiments including measuring the changes in light absorbance of a large number of samples mixed with different reagents in a progressive manner, biochemical, electrolytical, fluorescence, and immunological analysis and EIA analysis of samples in bead solid phase. A plurality of samples are maintained, together with diluents and emergency samples, in an ordered sequence on a sample table rotatably disposed which is rotated by drive means in a stepping manner to move the samples progressively to a predetermined suction position at which a sample pipetter picks up a measured amount of sample and dispenses it to one of a plurality of reaction containers that are arranged in an ordered sequence on a reaction table rotatably disposed, preferably about said sample table.

Abstract: A detecting device is fitted so as to span a row of adjoining receptacles which are set in a reciprocating continuous motion, so that each receptacle passes within the scanning field of the detecting device. The latter sends the signals sequentially to a processor for elaboration into point curves showing the courses of each reaction through time. The row of receptacles may be set in a reciprocating motion by a rack, a stepping motor, a cam-type control or a coupling device, etc.

Abstract: A method and apparatus for assaying a species in a biological sample fluid. The apparatus comprises an SAW device (1) comprising a slab (2) of piezoelectric material on the upper surface (5) of which is formed an input transducer (3) and an output transducer (4). A source of RF energy is applied to the input transducer to generate a surface acoustic wave. Applied to the surface (5) is a thin layer (8) of a material capable of binding a species to be assayed. The sample (13) to be tested is applied to the top of the layer (8). A collimated light beam (1) from a source (9) is applied to the thin film from underneath the slab (2) and is collected by a photodetector (12). When the slab (2) is energized, the vibration sets up an effective diffraction grating which is coupled to the thin film and acts to diffract the light beam (10) applied to it. The energy in the diffracted beam, as measured by the photodetector ( 12), is indicative of the progress and result of the reaction between the layer 8 and the sample.

Abstract: A radial immunodiffusion enzyme assay method for the simple estimation of immunoglobulins in humans and other animals, Agar test plates are provided including an underlying adherent coating of Staphylococcal Protein A antigen. Blood or blood serum samples from animals to be tested are placed in wells punched in the agar layer and allowed to incubate overnight. The agar gel is then removed. The resulting Protein A antigen layer with bound immunoglobulins from the samples is reacted with enzyme conjugated anti-immunoglobulin or enzyme conjugated Protein A. The reaction is visualized by overlaying the bound conjugate layer with agar containing a color producing enzyme substrate. The diameters of resulting colored zones permit estimation of total immunoglobulins. Methods of preparing Protein A antigen coated test plates are disclosed along with testing kits for carrying out the test procedure in the field.

Abstract: The use of the ability of immunologically non-specific peptide linked amino acid containing compounds to combine with anti-antibodies or rheumatoid factor to provide for a method of detecting rheumatoid factor and for a method of immobilizing circulating immune complexes from fluids for the purpose of detection or removal thereof from body fluids, such as serum or blood.

Abstract: A method of visualizing individual submicroscopic metal particles by subjecting said particles to bright field or epi-polarization microscopy and enhancing the contrast of the image so obtained by electronic means.

Abstract: A method is provided for determining the presence in a sample of a member of a specific binding pair ("sbp member") consisting of ligand and its homologous receptor. The sample is combined in an aqueous medium with (1) a complementary sbp member wherein at least the sbp member or the complementary sbp member is bound to the surface of a cell and (2) a fuorescent agent capable of being incorporated into the cell. The presence of the sbp member is indicated by a change in fluorescence of the unseparated cell suspension as a result of agglutination of the cells.The present invention has particular application to blood typing, for example, for the determination of the presence of blood group antigens A, B, AB, O, and D (Rh.sub.o) and antibodies to such antigens.

Abstract: An immunoassay device includes one or more reaction chambers. Each reaction chamber is adapted to receive and retain a volume of test fluid in fluid communication with nonoverlapping first and second reaction surfaces. To the first reaction surface is immobilized analyte binding partner that is in turn saturated with analyte conjugate: analyte component conjugated to one or more components, termed ligand/marker, that serve ligand and marker functions as described herein. The analyte conjugate has a higher disassociation constant with reference to the immobilized analyte binding partner than does the analyte to be assayed. To the second reaction surface is immobilized ligand/marker binding partner.A test fluid sample is introduced into the reaction chamber and retained therein to permit two reactions to occur. In a first reaction between analyte and analyte binding partner at the first reaction reaction surface, analyte proportionately displaces analyte conjugate into the test fluid sample.

Abstract: A cap for a container in which immunoassays are performed includes a liquid absorbing material accessible to liquid in the container.

Abstract: A device for carrying out chemical or clinical testing of a liquid sample, for example a urine sample, by a specific binding assay, said device comprising a test component (2) which has a sensitized solid surface (2a) carrying an immobilized component of a specific binding pair relevant to the assay, and a handling piece (1), and characterized in that the test component (2) bearing the sensitized surface (2a) is removably mounted in spaced relationship with a removably mounted accessory component (4) carrying an accessory solid surface (5), and in that there is a space (4a) between the sensitized surface (2a) and the removable accessory component (4) to act as a container for sample liquid, so that when the device is contacted with a sample liquid source or immersed in liquid which is to provide the test sample, liquid of the sample can enter the space (4a) to contact the sensitized surface (2a), and the accessory surface (5) acts to retain and contain sample liquid in contact with the sensitized surface (2a)

Abstract: A vertical beam spectrophotometer for measuring the light absorption of an assay prepared using standard wet chemistry procedures and conventional solid phase coated bead technology is disclosed. The spectrophotometer measures the absorption of the assay in a conventional reaction cuvette with the bead remaining in the cuvette. The light source of the spectrophotometer illuminates the bead, which diffuses the light into the surrounding assay solution. A lense projects the diffused light onto a photocell which converts it into an electrical signal having magnitude related to the light absorption of the assay. The signal is processed in a known manner by conventional processing circuitry to obtain an absorption value.

Abstract: An apparatus for determining a characteristic of a signal modulating component related to an analyte of interest at an assay site by measuring light modulated by the component. A light source uniformly illuminates the assay site and a reference site. The light is directed from the sites onto a group of memory cells on the surface of a random access memory. The memory cells will decay from a logical 1 to a logical 0 due to the light over a period of time which is a function of the intensity of the light and the reference voltage of the memory cells marking the difference between a 1 and a 0. The digital state of each of the memory cells in the group is measured a predetermined exposure time. The measured states of a group of memory cells corresponding to the assay site are compared to the memory cell states for a reference group. The measured states are then analyzed to determine a characteristic of the analyte.

Abstract: A device for performing a plurality of immunochemical assays simultaneously comprises a waste reservoir about which are positioned at least two assay tubes connected in series by conduits formed in the base and top of the reservoir structure. A compound syringe is insertable into an opening formed through the top of the waste reservoir, the syringe being held in place by a receiving structure formed in the base of the reservoir and connected to the entrance end of the series of assay tubes. The various compartments of the compound syringe are emptied in sequence to cause the flow of sample and assay reagents to flow through the assay tubes. The device is structured to allow for the reflow of sample through the tubes if desired.

Abstract: Disclosed herein is an apparatus and process for conducting ligand receptor assays. The apparatus comprises a first member which is a membrane or a filter to which is bound a receptor for the ligand or which is capable of extracting cells carrying the ligand from a fluid sample. The apparatus further comprises a second member which is composed of absorbent material which acts when in contact with the first member to induce flow through the first member when a fluid sample is added to it. The apparatus is used to conduct assays by applying a sample to the upper surface of the first member to bind ligand in the sample by means of receptor fixed to the first member or, in certain cases, by extracting cellular material which has ligand associated with it. Addition of the sample is typically followed by addition of labeled antibody against the antigen being assayed followed by a washing step to remove unbound labeled receptor.

Abstract: Methods, apparatus and sensors are described for detection of specific ligands in a fluid sample by measuring ligand-specific changes in the bulk electrical conductance (or resistance) of a fixed test volume, with antiligand or ligand localized in or near that volume.

Abstract: An improved process of performing analysis methods based upon biospecific affinity reactions in heterogeneous systems, wherein a ligand dissolved in a liquid is reacted with a receptor immobilized on a carrier, characterized by utilizing as the carrier a porous matrix in the form of a material body having an open capillary pore system capable of absorbing and retaining liquid phase and having such limited void dimensions that the total reaction rate of the biospecific reaction or reactions within the pore system between ligand and immobilized receptor will be at least substantially independent of the diffusion of the ligand in the liquid phase. A porous matrix for use in said process has the characteristics mentioned above.

Abstract: A microassay card having a three-layer laminate construction in which various recessed channels and chambers are interconnected with protruding flexible chambers and channels to provide a completely selfcontained analytical system adapted for treating and analyzing a sample utilizing a multiple microassay rod. The configuration of the various channels and chambers are arranged so that a wide variety of analyses involving numerous steps can be accomplished using the card. The card is activated and analysis and/or treatment carried out by passing a roller bar or other pressure device over the top of the card to force solutions and reagents through the various card channels. In addition, the movement of the pressure bar over the card closes and opens various channels within the card to provide controlled and programmable transfer of solutions during treatment of the microassay rod.

Abstract: Devices and methods are provided for making a plurality of determinations of the local (site-specific) redox state of a liquid system, by employing a photoresponsive element, which can be independently irradiated at different sites to provide independently detectable signals.

Abstract: An enzyme immunoassay device comprises a disk having a thin flexible membrane applied to one side thereof, the membrane defining a conduit and a plurality of reagent reservoirs. The reservoirs are isolated from one another or from the conduit by frangible seals. An assay tube having an assay reagent bonded to the inner wall thereof is attached to the exit end of the conduit. Means are provided for injecting a test sample into the conduit for flowing thereof through the assay tube. Means are also provided for forcing the contents of each reservoir through the conduit and assay tube in the desired order by causing the rupture of each frangible seal sequentially.

Abstract: This invention relates to the use of differential separative properties and modified assay containers in improving the convenience of separative scintillation proximity assay (SSPA) and extending its range of practical application.

Abstract: The subject invention provides a means for the immunological detection of an entire class of microorganisms in clinical samples. The detection is accomplished by reaction of the clinical sample iwth a class-specific immunological reagent. This reagent is an antiserum either monoclonal or polyclonal in nature, and the detection is based upon reaction of the antiserum with an antigenic determinant which is shared among all members of the detectable class of microorganisms. The presence of the resulting immunological reaction product (e.g. the antigen-antibody complex) may be detected by well-known immunological detection-systems.

Abstract: An immunoassay of a specimen of a serum or the like to determine the composition of immune complexes, includes producing on a plastic base a layer of a non-proteinaceous, non-ionic polymer which will adhere to the plastic base and has the capability of adsorbing immune complexes of the specimen, placing a specimen on the layer and treating the layer to produce an indication of the composition of the immune complexes. The polymer may be polyethylene glycol, dextran, polyvinyl chloride, a polymeric polyol or an adduct of polyethylene glycol or mixtures thereof. Washing with conventional solutions, addition of monoclonal and/or polyclonal antibodies coupled with an enzyme and addition of a substrate reactive therewith to determine the antigen component, are similar to the ELISA test, with color measurement as by spectrophotometer. Or, the addition of anti IgG-I.sup.125 and measurement by a scintillation counter may be used. Addition of IgG, IgA, IgE, IgG.sub.

Abstract: An assay card having a three-layer laminate construction in which various recessed channels and chambers are interconnected with protruding flexible chambers and channels to provide a completely self-contained analytical system adapted for treating and analyzing a sample utilizing a multiple assay rod. The configuration of the various channels and chambers are arranged so that a wide variety of analyses involving numerous steps can be accomplished using the card. The card is activated and analysis and/or treatment carried out by passing a roller bar or other pressure device over the top of the card to force solutions and reagents through the various card channels. In addition, the movement of the pressure bar over the card closes and opens various channels within the card to provide controlled and programmable transfer of solutions during treatment of the microassay rod. An assay rod having fluorescent marker layers is provided for use in analysis methods utilizing fluorescently marked detection substances.

Abstract: An assay apparatus employing total internal reflection of excitation radiation at the interface between an optically conductive rod or fiber and a surrounding liquid phase of lower index of refraction. Immobilized on the surface of the fiber is a component of a complex formed in an immunochemical-type reaction; a fluorophore that can be excited into fluorescence by the excitation radiation is attached to another component of the complex. The fiber is coaxially disposed in cantilevered manner within a length of tubing, so that the excitation radiation can be launched into the unsupported end of the fiber and the fluorescent radiation tunneling back into the fiber may be observed at the same fiber end, thereby preventing that portion of the fiber surface between the unsupported fiber end and the mounted end being in contact with other than the surrounding liquid phase.

Abstract: An apparatus responsive to optical changes in a waveguide when the latter is contacted with an analyte capable of reacting with a specific reactant thereto attached to the surface of said guide involves, for containing the analyte, an interchangeable round bottomed cuvette temporarily held by a suitably shaped carrier in working relationship with the optical components of the apparatus, this arrangement ensuring a correct optical orientation thereof relative to said component whatever the exact positioning of the cuvette.

Abstract: Assay for a hapten or antigen wherein supported hapten or antigen is used to separate "bound" and "free" fractions. The sensitivity of the assay is increased.

Abstract: A device is disclosed into which a test solution can be added and at least the first step of a specific binding assay can be carried out. The device comprises a two compartment tube containing a removable rod having at one end a plurality of filaments coated with a specific binding partner for the analyte to be determined.

Abstract: A method is provided for solid phase immunoassay for quantitation of antigen, hapten or antibody analyte in liquid sample and alternatively for quantitation of analyte occuring on or attached to cells or other particulate material in a liquid sample. The solid phase is suspended for at least the initial reactions and is subsequently concentrated by microfiltration to a volume substantially less than the sample volume. Luminescence of substantially the entire label on the concentrated solid phase is measured.

Abstract: A portable apparatus to enable rapid determination of an individual's ABO blood group and Rh blood type and a method of using such apparatus. The apparatus has a plurality of microtubes joined together which contain blood taken from an individual. The assembly of microtubes is connected during use to an assembly of reaction chambers containing blood typing reagents. The apparatus enables rapid visualization of the test reactions within the reaction chambers, and may be used in locations removed from a laboratory to determine the ABO blood group and Rh blood type of an individual.

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: The present invention relates to a simple and accurate method to be applied in immunoassay technique for separating the free ligand from the antibody-bound ligand.The method involves the use of a solvent extraction operation which at equilibrium provides the formation of two distinct phases the free- and bound-fraction. The solvent to be utilized should be slightly water miscible or completely water immiscible, having the property of marked selective extraction power toward the gamma-labelled constituent to be determined. The method is applicable in a liquid-liquid system, a solid-liquid system and solid-solid system.The method is useful for radioimmunoassay, free radical assay or metallo-immunoassay, being most versatile having also the advantage that as a result of the free ligand being extracted into the solvent, the determination of the quantity of gamma-labelled substance in the free and/or bound fraction compares very favorably with the known prior art methods in immunoassays.

Abstract: The reagent is constituted by a suspension of basophil granulocytes bearing specific IgE's, containing from 300 to 1000 basophils per mm.sup.3. This suspension is obtained from a blood sample taken from a human or animal patient, by means of a liquid of density 1.079-1.085. It is deposited in the various wells of a diagnosis read-out slide or the like, for diagnosing parasitoses or allergies. The diagnosis method is applied particularly to worm parasitoses which causes an increase in the circulating specific IgE's. The diagnosis may be carried by using ready-for-use kits.

Abstract: Disclosed herein is an apparatus and process for conducting immunoassays. The apparatus comprises a first member which is a membrane or a filter to which is bound an antibody, typically a monoclonal antibody, or which is capable of extracting cells from a fluid sample. The apparatus further comprises a second member which is composed of absorbent material which acts when in contact with the first member to induce flow through the first member when a fluid sample is added to it. The apparatus is used to conduct immunoassays by applying a sample to the upper surface of the first member to bind antigen in the sample by means of antibody fixed to the first member or, in certain cases, by extracting cellular material which has antigen associated with it. Addition of the sample is followed by addition of labeled antibody against the antigen being assayed followed by a washing step to remove unbound labeled antibody.

Abstract: An automated system for rapid sequential photometric analysis of a collection of double fluorochrome stained lymphocyte specimens, useful for antibody screening or lymphocytotoxicity analysis. The specimens are sequentially alternately irradiated with light of two distinguishable wavelengths, producing fluorescence at two distinguishable wavelengths. The fluorescent emission light intensity for each irradiation of each specimen is measured using a photometer and computer. The computer controls the synchronization of the irradiation through alternately selected condenser sets with the sequential movement of specimens into the optical path of the irradiating and detected light, and calculates the quotient of the light intensities emitted from each specimen at the two selected fluorescent light wavelengths. These quotients are compared against a control ratio (for lymphocytotoxicity analysis) to classify the specimen.

Abstract: A process and apparatus has been developed for radioassay of ligand in solution which eliminates the separation step required in conventional techniques. A chamber is provided containing a quenching solution, a plurality of ligand molecules and a plurality of receptor molecules. One of pluralities forms a free species labelled with a beta particle emitter while the other is immobilized on a solid support, e.g., the chamber wall or a microbead, within the chamber. Ligand introduced with the sample competes with ligand molecules already in the chamber for receptor sites on the receptor molecules and the free species is allowed to diffuse about the chamber. A beta particle detector in communication with the chamber at a fixed position detects only those beta particles emitted from within the quenching distance of the quenching solution. The quenching properties of the solution are used in place of the conventional separation step.

Abstract: The present invention discloses a device and a process for quantitation of end point in the formation of fluorescent reaction product in microfluorophotometry. The process comprises:(a) incorporating a protective agent in a suitable mounting medium in an amount sufficient to reduce fading of fluorescent reaction product less than 25% of initial fluorescent intensity;(b) calibrating photometer used in said microscopy with a stable emitter; and(c) recording the intensity of fluorescence of said fluorescent reaction product by means for measuring light intensity.The invention also includes a device for calibration of the photometer and a kit comprising separate containers for suitable mounting medium, buffer, suitable immunofluorescent reagents, fading retardant means, a photometer calibrating device and the like and optional instructions.

Abstract: The invention provides improved methods and unique instrumentation for the detection and for the quantitation of chemical substances and has particular application for the detection and for the quantitation of immunological substances.

Abstract: A process for `unmasking` delta antigen in the blood of an animal, known or caused to be infected with the antigen. The process involves treating serum from the animal with a surfactant and optionally with an antibody--antigen dissociating agent. The blood derived delta antigen is used as a diagnostic agent in the detection and determination of different classes of antibodies to hepatitis D. virus (delta agent) by enzyme-immunoassay and radio-immunoassay.

Abstract: There is presented a novel immunological element suitable for an immunological assay of an antigen according to the so called two antibody method, which element having two separate sheets, one being a sheet for reaction in which the reaction for formation of antigen-antibody bounds is carried out and the antigen-antibody bounds formed are immobilized, the other being a F receptor sheet in which unreacted free labelled antigen is transferred at a controlled rate to be received for analysis. This element enables separation between the bounds and the free labelled antigen by a simple operation without cumbersome separation procedures and is also excellent in storability.

Abstract: There is disclosed an immunoassay comprising carrying out an immunological reaction by contacting a fluid sample with an element for immunoassay, having at least three layers of a first detecting layer, a blocking layer and a second detecting layer which are successively laminated, the element containing a substance capable of binding specifically to an immunologically active substance in a fluid sample only in either one of the first and the second detecting layers, and then measuring the detected quantities corresponding to the immunological reaction quantities from both of the first and the second detecting layers.The immunoassay by the use of the immunological analytical element according to this invention improves the precision immunoassay by measuring both of Bound and Free.

Abstract: A field emission chemical sensor for specific detection of a chemical entity in a sample includes a closed chamber enclosing two field emission electrode sets, each field emission electrode set comprising (a) an electron emitter electrode from which field emission electrons can be emitted when an effective voltage is connected to the electrode set; and (b) a collector electrode which will capture said electrons emitted from said emitter electrode. One of the electrode sets is passive to the chemical entity and the other is active thereto and has an active emitter electrode which will bind the chemical entity when contacted therewith.

Abstract: For microbiological and other laboratory work in which an active substance is contacted with a substrate there is provided a container for the substrate and a divided carrying body with respective separated sections in sealed contact within the container such that the sections form separate regions with isolated substrate portions in each of the regions. The active substance is supported by the carrying body and is immersed in the respective isolated substrate regions so that it can be diffused into the substrate portions.

Abstract: A method of composition is featured for performing a fluoroimmunoassay of a biological fluid sample for an immunological reactant. A conjugate of a carrier labelled with fluorophores and coupled to an immunological reactant is mixed with the sample and a known quantity of binding agent. After equilibrium is accomplished, the bound and unbound portions are separated. The carrier in a selected portion is chemically treated to liberate the fluorophores. The fluorescent level is then measured and compared with a standard.