Abstract: Immunoassays of psychoactive drugs including psychotomimetic drugs, narcotic drugs, and tetrahydrocannabinols and treatment methods based on the antigenic properties of protein conjugates of these drugs. These methods are based upon treating the psychoactive substances as haptens and utilizing their protein conjugates to produce antibodies to the psychoactive materials themselves. The immunoassay methods include both agglutination and agglutination-inhibition reactions. The treatment methods include treatment or both exogenous, administered drugs (such as cannabinols, LSD, heroin and morphine) and endogenous substances (such as N,N-Dimethyltryptamine and 5-Methoxy-N,N-Dimethyltryptamine, by active immunization and also passive immunization.

Abstract: Surfaced-enhanced, analytical procedures wherein a surfaced article includes a substrate surface, metal islands, a spacing/coupling agent layer, and binding partner molecules which bond with work piece molecules to be detected. A population of spaced apart metal islands are formed on the substrate and have at least some interconnections formed between them. A continuous layer coats the islands and all surfaces between the islands. The continuous layer includes a coupling agent which immobilizes first binding partner molecules. The first partner molecules bond to the coupling agent and the second binding partner molecules bind to the first binding partner molecules to allow detection of presence or concentration of the work piece binding partner molecules.

Abstract: Ligands that interact with a target can be more easily identified if false positive interactions (either specific or non-specific) from the detecting system are differentiated from the target-specific interaction. An improved method of identifying peptides which bind with a target protein is presented. The steps are: binding a random library of peptides to a support material, allowing detection reagents to contact the peptides and the support material then identifying these interactions, then allowing the target protein to selectively bind to the peptides, allowing detection reagents to contact the bound target protein, and characterizing the peptide bound to the identified support material. Interaction of a ligand or the support material with the detection reagents will cause a distinct color change which distinguishes those ligands which selectively bind to target protein. The characterized peptide can then be used in affinity purification of the target protein.

Abstract: Anti-human stromelysin monoclonal antibodies reactive with latent and active forms of stromelysin without discrimination between the two, each being immunoreactive with only one of the antigenic determinants of human stromelysin, are provided. The use of a combination of two such monoclonal antibodies which specifically react with different antigenic determinants of human stromelysin renders it possible to accurately determine the amount of human stromelysin in human body fluids, and thus to carry out the diagnosis of rheumatoid arthritis.There are thus provided said monoclonal antibodies per se, a sandwich enzyme immunoassay for the determination of the amount of human stromelysin in human body fluid samples using a combination of two such monoclonal antibodies, and a method for the diagnosis of rheumatoid arthritis using said immunoassay.

Abstract: A patient's health may be diagnosed by centrifuging blood samples in a transparent tube, which tube contains one or more bodies or groups of bodies such as floats, inserts, liposomes, or plastic beads of different densities. Each density-defined body carries analyte-capture binding materials such as antigens or antibodies, which are specific to an epitope, or other specific high affinity binding site on a target analyte which target analyte may be in the blood or other sample being tested; and the level of which analyte is indicative of the patient's health. At least one labeled binding material which is also specific to an epitope, or other specific high affinity binding site on the target analyte is added to the sample so as to form labeled binding material/analyte/body complexes in the sample.

Abstract: The present invention provides a novel carbamazepine hydrazide compound suitable for covalent attachment to a polymer particle reagent, having the general formula ##STR1## The present invention also provides a novel carbamazepine acid compound suitable for attachment to proteins for the production of carbamazepine immunogens. The carbamazepine antigen of the present invention has the following general structure: ##STR2## where X is C.dbd.O, CH.sub.2 or SO.sub.2 ; Y is C.dbd.O, CH.sub.2, SO.sub.2 ; R is an alkyl and P is a protein or a hapten.

Abstract: Methods for determining the presence of a ligand in a sample suspected to contain the ligand are provided, along with apparatus suitable for performing the methods. The methods depend upon a color visualization indicating the ligand's presence or absence in the sample. Preferred methods comprise contacting the sample with colored particles which bear on their surface a receptor specific for the ligand, passing the sample/particle mixture through a filter, and then analyzing the color of the filtrate. The presence of ligand in the sample is established where the color of the filtrate is substantially different from the color of the receptor-bearing particles.

Abstract: The invention relates to a glycosylated particle of latex or of inorganic oxide, exhibiting functional radicals at the surface. At least a proportion of said functional radicals is joined to a glycosyl residue.The particles preferably consist either of polymers obtained by polymerization of ethylenically unsaturated monomers or of silica.The invention finds an application as a detection agent in biology.

Abstract: Sets and libraries of sets of polypeptides that are related in sequence to melittin are disclosed that have antimicrobial, hemolytic and hydrolytically catalytic activities, as are processes for making and using the same. A contemplated set is a mixture of equimolar amounts of a polypeptide of SEQ ID NO:2, and more preferably SEQ ID NO:3.

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 are disclosed for determining an analyte in a medium suspected of containing the analyte. One method comprises treating a medium suspected of containing an analyte under conditions such that the analyte, if present, causes a photosensitizer and a photoactive indicator precursor molecule to come into close proximity. The photosensitizer generates singlet oxygen which activates the photoactive indicator precursor to generate a photoactive indicator molecule. Upon irradiation with light the photoactive indicator molecule produces light, which is measured. The amount of light produced by the photoactive indicator is related to the amount of analyte in the medium. Compositions, kits, and compounds are also disclosed.

Abstract: The invention provides a method of assessment of carbohydrate-deficient transferrin in a transferrin containing body fluid, said method comprising the steps of:i) obtaining a transferrin containing liquid sample of or derived from a said fluid;ii) contacting said sample with a source of iron ions;iii) subsequently contacting said sample with an anionic ion exchange resin at a pH such as to cause carbohydrate-deficient transferrin to be retained by said resin;iv) subsequently contacting said resin with an eluant serving to release carbohydrate-deficient transferrin into the eluate from said resin;v) collecting a volume of said eluate substantially free from tetra- and penta-sialo transferrin; andvi) assessing the transferrin variant content in said volume of eluate.By including at least a proportion of the trisialotransferrin in the eluate, it is possible to use relatively simple assessment techniques such as turbidimetry in the assay.

Abstract: Encoded combinatorial chemistry is provided, where sequential synthetic schemes are recorded using organic molecules, which define choice of reactant, and stage, as the same or different bit of information. Various products can be produced in the multi-stage synthesis, such as oligomers and synthetic non-repetitive organic molecules. Conveniently, nested families of compounds can be employed as identifiers, where number and/or position of a substituent define the choice. Alternatively, detectable functionalities may be employed, such as radioisotopes, fluorescers, halogens, and the like, where presence and ratios of two different groups can be used to define stage or choice. Particularly, pluralities of identifiers may be used to provide a binary or higher code, so as to define a plurality of choices with only a few detachable tags. The particles may be screened for a characteristic of interest, particularly binding affinity, where the products may be detached from the particle or retained on the particle.

Abstract: A test device for detecting or determining an analyte in a test solution includes an absorbent material having separate contact, competitive binding, and measurement portions. The contact portion is positioned for contact with and uptake of the test solution. The competitive binding portion has a binding material for the analyte non-diffusively bound thereto. The measurement portion has a receptor for the analyte and marker-encapsulating liposomes non-diffusively bound thereto. In a method for using the test device, a solution containing the analyte and the analyte-liposome conjugate is allowed to traverse the absorbent material from the contact portion through the competitive binding portion and on through the measurement portion of the absorbent material. The amount of marker in the measurement portion of the absorbent material, following traversal by the test solution, is then determined as a measure of the analyte in the sample.

Abstract: The invention relates to the area of protein determinations in homogeneous solution by means of antigen-mediated precipitation by antibodies or using latex materials coated with antibodies and subsequent optical measurement of the precipitation reaction by a nephelometric or turbidimetric measurement.

Abstract: A method of assaying for CAT in a fluid involves the use of a complex of chloramphenicol with a member of a specific binding pair such as a hapten or biotin. Biotinylated chloramphenicol is claimed as new. A scintillation proximity assay involves use of this reagent with tritiated acetyl coenzyme A and streptavidin coated SPA beads.

Abstract: The invention describes novel fluorescently labeled microspheres, where the microspheres possess at least one internal fluorescent spherical zone. The invention also describes the method of preparing the novel microspheres, the method of calibrating microscopy instrumentation using the novel microspheres, the method of using the novel microspheres as distinct labels for combinatorial analysis and the use of the labeled microspheres as tagging agents and tracers.

Abstract: A device for detecting the presence of substances, particularly biological materials, contained in a liquid sample is formed of a series of layers of film materials. A first film has a cut-out which forms an upper reservoir for receiving the liquid sample. A first reagent is provided in the upper reservoir capable of reacting with a substance possibly contained in the liquid sample. A first membrane is situated at the base of the upper reservoir and is made of a material which is temporarily impermeable so that the liquid sample is temporarily retained in the upper reservoir in contact with the first reagent, but after awhile the membrane becomes permeable and allows the liquid to pass. A second film has a cut-out which forms a median reservoir positioned for receiving the liquid passing through the first membrane. A second reagent is provided in the median reservoir capable of reacting with a predetermined substance.

Abstract: Liposome reagents used in assays to detect the presence or amount of an analyte in a test sample, particularly where the analyte is antiphospholipid antibodies are described. The liposome reagents comprise a liposome, a ligand chosen to bind specifically with the analyte and associated with the liposome membrane, and a haptenated component associated with the membrane of the liposome where the hapten is chosen to bind specifically to a receptor bound to a solid phase or to a label compound that is an element of a signal detection system and where the liposome reagent is prepared so that during the assay the linkage between the solid phase and ligand of the liposome reagent is maintained.

Abstract: A patient's health may be diagnosed by centrifuging blood samples in a transparent tube, which tube contains one or more bodies or groups of bodies such as floats, inserts, liposomes, or plastic beads of different densities. Each density-defined body carries analyte-capture binding materials such as antigens or antibodies, which are specific to an epitope, or other specific high affinity binding site on a target analyte which target analyte may be in the blood or other sample being tested; and the level of which analyte is indicative of the patient's health. At least one labeled binding material which is also specific to an epitope, or other specific high affinity binding site on the target analyte is added to the sample so as to form labeled binding material/analyte/body complexes in the sample.

Abstract: A method for determining an analyte in a sample which includes: providing the sample in liquid phase, the analyte of which has a ligand having at least one anti-ligand specific recognition site; providing at least one reagent containing metal particles, in suspension in liquid phase and non-separable from the liquid phase by a magnetic or electromagnetic force, each particle containing a metal core to which at least one anti-ligand is fixed directly or indirectly; contacting the sample and the at least one reagent in order to obtain metal clusters; placing the metal clusters in a magnetic field generated by a magnetic or magnetic field generating sensor in order to assemble the metal clusters; and detecting the assembled metal clusters to obtain a signal representative of the mass of metal in the clusters, which is correlated with the quantity of analyte present in the sample initially. A device for determining an analyte in a sample by the above process is also included.

Abstract: A particularly efficient design for a nonbibulous lateral flow one step assay for an analyte in a biological sample is disclosed. In the improved device of the invention, three zones which are in nonbibulous lateral flow contact are employed: a sample receiving zone, a labeling zone, and a capture zone. The sample containing analyte is carried through the labeling zone and interacts with an assay label comprising visible moieties, preferably particles, which are coupled to specific binding reagent for analyte or to a competitor with analyte for a capture reagent. The flow continues into the capture zone where the visible moieties to which analyte or competitor are coupled are captured. Excess fluid is absorbed into an absorbent zone in contact with the capture zone. A positive result is obtained by visualizing the visible moieties in the capture zone.

Abstract: What is described are methods and apparatus for performing a binding assay for an analyte of interest present in a sample. The methods include the steps of: forming a composition containing said sample, an assay-performance-substance which contains a component linked to a label compound capable of chemiluminescing when triggered, and a plurality of coated magnetic particles capable of specifically binding with the analyte and/or said assay-performance-substance; incubating said composition to form a complex which includes a particle and said labeled component; magnetically collecting said complex at the surface of an electrode; inducing said label to luminesce by contacting it with a trigger, said trigger being formed in-situ by conversion of a precursor molecule upon introduction of electrochemical energy; and measuring the emitted luminescence to measure the presence of the analyte of interest in the sample.

Abstract: A particularly efficient design for a nonbibulous lateral flow one step assay for an analyte in a biological sample is disclosed. In the improved device of the invention, three zones which are in nonbibulous lateral flow contact are employed: a sample receiving zone, a labeling zone, and a capture zone. The sample containing analyte is carried through the labeling zone and interacts with an assay label comprising visible moieties, preferably particles, which are coupled to specific binding reagent for analyte or to a competitor with analyte for a capture reagent. The flow continues into the capture zone where the visible moieties to which analyte or competitor are coupled are captured. Excess fluid is absorbed into an absorbent zone in contact with the capture zone. A positive result is obtained by visualizing the visible moieties in the capture zone.

Abstract: An immunoagglutination reagent includes liposomes, as a carrier, with a covalently bound antigen or antibody immobilized thereon. The reagent is used to assay an antibody or an antigen on the basis of agglutination. The assaying can be done at a high sensitivity in the short wave region where the change in turbidity caused by the agglutination is enhanced. An antibody or an antigen is immobilized onto the surface of the liposome, and a water-soluble polymer compound or a gelled compound is entrapped in the liposomes. The substance entrapped in the immunoagglutination reagent enhances the change in turbidity via the agglutination caused by the antigen-antibody reaction.

Abstract: A test device for detecting or quantifying an analyte in a test sample includes an absorbent material having separate contact and measurement portions. The contact portion is positioned at or proximate to a first end of the absorbent material. The measurement portion has a receptor for a conjugate of an analyte analog and marker-encapsulating liposomes. In a method for using the test device, a binding material specific for the analyte is combined with the liposome-analyte analog conjugate and the test sample to form a test mixture. The mixture is incubated for a time sufficient to permit competition between any analyte present and the conjugate for the binding material. Following incubation, the mixture is allowed to traverse the absorbent material from the contact portion through the measurement portion of the absorbent material.

Abstract: Quantitative immunochromatographic assays for measuring the amount of an analyte, and an apparatus for use in the assays, are disclosed. The assays involve obtaining a fluid sample which contains the analyte; supplying a RAMP.TM. apparatus which includes a membrane having an application point, a detection zone, and a contact region, where the contact region is between the application point and the detection zone, and has antibody-coated particles imbedded within it; contacting the application point with the fluid sample; maintaining the RAMP.TM.

Abstract: A detectable synthetic copolymer useful to detect the presence of a microorganism in a test sample is provided. The copolymer comprises repeating monomeric units, which incorporate a population of first monomeric units each comprising a binding agent which binds to a microorganism having multiple binding sites for said binding agent and which further incorporates a population of a second monomeric units each comprising a detectable label or a binding site for a detectable label.

Abstract: A variant of a LAV virus, designated LAV.sub.ELI and cable of causing AIDS. The cDNA and antigens of the LAV.sub.ELI virus can be used for the diagnosis of AIDS an pre-AIDS.

Abstract: A method and apparatus for determining qualitatively or quantitatively the presence of analyte bound to a separation media without doing a bound/free separation. In the method, the bound fraction is collected in an assay region of a body of liquid which includes the free analyte, and the assay is performed by comparing the radiant-energy response in the assay region to the radiant-energy response in a control region of the body of liquid which is free of bound analyte. The apparatus has a chamber which contains the body of liquid, one or more collection elements and a control element and position in the body of liquid parallel to an opaque wall which has a colliminating slit in registry with each element. Each slit enables sensing of the radiant-energy response from the body of liquid between the slit and its associated elements.

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: There are disclosed a magnetic particle for an immunoassay method, which comprises a core and a coating layer formed on the surface of the core wherein said core comprises an organic polymer matrix and said coating layer comprises a mixed crystal ferrite represented by the formula:M.sub.x Fe.sub.(3-x) O.sub.4wherein M represents at least one metal selected from the group consisting of Mn, Ni, Zn, Co, Cu, Mg, Sn, Ca and Cd, and x is a number satisfying the relation: 0<x<3,and an antigen or an antibody is bound onto the surface of the coating layer and wherein said particle has a particle size of 0.03 to 10 .mu.m, and an immunoassay method using the same.

Abstract: Device for capturing a target molecule for the purpose of detecting it and/or assaying it, including a solid support on which is immobilized a ligand, the ligand being provided in the form of a conjugate resulting from the covalent coupling of a polymer with a plurality of molecules of the ligand. The polymer is an N-vinylpyrrolidone copolymer, and the conjugate is immobilized on the solid support by adsorption.When the ligand is capable of forming a complex with the target, the device is specific for a given target. When the device comprises, in addition, a bifunctional reagent capable of forming a complex, on the one hand, with the ligand and, on the other hand, with the target, the support on which the ligand is immobilized constitutes a universal capturing system.

Abstract: The present invention relates to a binary assay method capable of providing wide dynamic range and a high degree of precision in which analyte and labelled ligand are reacted with two independently determinable forms of solid-supported binding partners having affinity for the analyte and labelled ligand, respectively. The analyte concentration is determined from signals deriving from the resulting two forms by reference to a double standard calibration curve. A kit for use in the method is also disclosed.

Abstract: The invention relates to a method of detection, a sensor and a test-kit which find application in immunological detection (e.g., immunoassay). The invention provides, inter alia, a method of detection, suitable for use in immunological detection of an entity, which method includes the use of a secondary species (as defined in the specification), the use of a first detectable species, and the use of a second detectable species. The method may include, for example, the use of a primary species, a secondary species, a first detectable species and a second detectable species. The primary species may be, for example, an antibody or a ligand. The secondary species may be, for example, an auxiliary species such as an auxiliary binder or an auxiliary ligand, or a species which has a part which is an auxiliary function. The entity to be detected may be an analyte species as such or may be an entity which carries or includes analytes species.

Abstract: Encoded combinatorial chemistry is provided, where sequential synthetic schemes are recorded using organic molecules, which define choice of reactant, and stage, as the same or different bit of information. Various products can be produced in the multi-stage synthesis, such as oligomers and synthetic non-repetitive organic molecules. Conveniently, nested families of compounds can be employed as identifiers, where number and/or position of a substituent define the choice. Alternatively, detectable functionalities may be employed, such as radioisotopes, fluorescers, halogens, and the like, where presence and ratios of two different groups can be used to define stage or choice. Particularly, pluralities of identifiers may be used to provide a binary or higher code, so as to define a plurality of choices with only a few detachable tags. The particles may be screened for a characteristic of interest, particularly binding affinity, where the products may be detached from the particle or retained on the particle.

Abstract: A dry immunoassay analytical element, for assaying a ligand is disclosed. The element comprises, in the following order, (a) a layer containing a labeled ligand, (b) a bead spreading layer, c) a cross-linked hydrophilic polymer layer and d) a support; wherein(i) a fixed concentration of an immobilized receptor for the labeled ligand is located in a zone at the interface of layers (b) and (c); and(ii) the receptors are immobilized by being covalently bonded to polymeric beads that are smaller than the beads in layer (c).

Abstract: This invention relates to a lateral flow immunochromatographic assay device without a plastic housing. The assay includes a sample receiving region, analyte detection region and end region all made of porous material and capable of lateral flow. The analyte detection region includes labeling reagents, a capture reagent and a control reagent. The back of the porous material is laminated with a semi-rigid material with adequate mechanical strength. The top is partially covered with a thin plastic material so as to leave a portion of the sample receiving region exposed for sample application.

Abstract: Assays using receptor:reland complexes capable of releasing the reland in the presence of an analyte are described, wherein the reland does not detectably compete with analyte for binding to the receptor. The dissociation constant of the reland and the receptor is such that no appreciable release of reland occurs in the absence of analyte for the receptor. In a preferred embodiment, the association constant of the monomeric reland and the receptor is less than or equal to about 10.sup.5 M, preferably 10.sup.3 to 10.sup.5 M, most preferably 1% or less of the association constant of the analyte and receptor. In a preferred embodiment, the reland is labelled and the amount of analyte bound to the receptor is determined from the amount of labelled reland which is released.

Abstract: SLO peptide antigens are described. These peptide antigens are suitable for the determination of SLO antibodies, as immunogens for the production of antibodies against SLO and as vaccines for the production of vaccines against SLO.

Abstract: Stabilized microspherical particles having hydrophobic liquid cores prepared as oil-in-water microemulsions. The particles are stabilized by a surface layer comprising an amphiphilic compound and may be functionalized to allow covalent coupling of a ligand to the surface of the particle. When used as tracers in assays, a water insoluble dye may be incorporated in the core liquid of the microparticles.

Abstract: A dry immunoassay analytical element for assaying a ligand, comprising a support bearing:1. an enzyme labeled ligand or an enzyme labeled receptor zone;2. a spreading zone; and3. a receptor zone containing a fixed concentration of an immobilized receptor for the ligand and the labeled ligand when present 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 diaryl telluride (DAT) compound and the zones can be in the same or separate layers.

Abstract: A "one step" device for the detection of analytein clinical assays is disclosed. A visible label comprising a visible moiety and a ligand that binds to or competes with analyte is contained in a fluid conducting membrane or prefilter; and the analyte and associated ligand are conducted by the flow of sample into a detection zone. The detection zone contains a capture reagent that binds to label or to analyte bound to label.

Abstract: The invention is a rapid, continuous test for glycated hemoglobin using a non-equilibrium affinity binding method. Agarose beads derivatized with 3-aminophenylboronic acid specifically bind glycated hemoglobin. This solid phase is incorporated into a sample processor card, modified to mix and to separate the test solution from the solid phase prior to absorbance readings. Two absorbance readings are made on the test solution, one immediately after mixing the reagent/diluent with the specimen, and one after a significant amount of binding has occurred. A linear correlation between total glycated hemoglobin and hemoglobin A.sub.1c permits standardization and reporting of units equivalent to % hemoglobin A.sub.1c. Stable glycated hemoglobin solutions for use as standards in the assay, and a method for preparing the standards are also disclosed.

Abstract: A method of immunologically assaying intact human osteocalcin in a human assay sample is provided by using an antibody having an epitope in a region of an amino acid sequence 1 to 20 on the N-terminal side of human osteocalcinand an antibody having an epitope in a region of an amino acid sequence 36 to 49 on the C-terminal side of human osteocalcin. Furthermore, a method of immunologically assaying the total amount of human intact osteocalcin in a human assay sample is provided. A reagent and a kit therefor are also described, as well as a monclonal antibody and a polyclonal antibody used for the assay a process for producing these antibodies; and a process for use of these antibodies.

Abstract: A method for increasing the binding activity of specific binding members bound to a solid phase material, e.g., a particle, that has been sterically stabilized. This increase in binding activity is brought about by degrading a steric stabilizer on the surface of the solid phase material. The method involves both immobilizing a specific binding member on the surface of a solid phase material and degrading a steric stabilizer on the surface of that solid phase material. In the preferred embodiment, the method involves the immobilization of a specific binding member on the surface of the sterically stabilized solid phase material, with subsequent degradation of the steric stabilizer.

Abstract: Insoluble supports are prepared which possess high surface areas and efficiently dispersed isocyanate groups. These reactive supports are useful for covalently binding proteins which preferably are enzymes and provide catalysts for conducting organic reactions.

Abstract: A method for detecting a target substance which includes collecting a substance sample; introducing the substance sample into a substance card having at least one reagent responsive to the presence of the target substance and having a light-transmissive chamber; inserting the substance card into a substance detector device having a photosensor and adapted to receive the substance card; mixing the substance sample with the reagents for a preselected mixing period, thus producing a measurand having a target substance reaction; streaming the measurand through the light-transmissive chamber and illuminating the measurand with a quantity of light for a selectable analysis period, an optical characteristic of the measurand can be measured with the photosensor; and selecting the target substance reaction as a positive reaction or a negative reaction, responsive to the optical characteristic. If the target substance reaction is a negative reaction, the device operator is signalled thereof.

Abstract: The present invention is a method and apparatus useful for the detection of bloodgroup antigens and antibodies. There are two preferred embodiments of the method: a direct assay and an indirect assay. The direct assay comprises adding a sample of erythrocytes to a reaction tube charged with a column of immunoreactive particles having an immunoglobulin binding ligand selected from the group consisting of Protein A, Protein G, Protein A/G or a universal kappa light chain binding protein coupled to the surface of the particles. Antibodies specific for bloodgroup antigens tested for are coupled to the ligand on the particles. The reaction tube is then centrifuged for a time sufficient to force to the bottom of the reaction tube erythrocytes that do not attach to the antibodies on the particles.

Abstract: A multi-purpose on-line or field-portable system and method for monitoring the presence and concentration of selected antigen-antibody reactions singly or in combination that result from the presence of specific microorganisms or free antigens present or suspended in aqueous solutions, during a given time period. The detection system comprises a detection column and two sensors mounted around the detection column. Each sensor consists of an electromagnetic radiation source and an appropriate detector for the electromagnetic radiation. The reacted analyte tends to accumulate at the sensor located at the bottom detection column. The lower sensor continually nulls against the upper sensor to subtract any optical effects due to non-reactants in the aqueous process or environmental stream. The response from the detector sensors drive an electric circuit, which provides an output signal. In the on-line automatic version, the signal can drive elements of a process system by switching automated valves.