Abstract: A method for substantially preventing coating of hydrophobic material on a probe of an automated analyzer during an assay is described. An automated analyzer having a probe is provided. A composition comprising a non-denaturing surfactant and a reagent for use in the assay is provided. The probe is contacted with the composition during the assay such that hydrophobic material is substantially prevented from coating the probe on the automated analyzer. Compositions for preventing such probe coating are also described. Methods and compositions comprising a non-denaturing surfactant for enhancing the stability of reagents used in an assay are also described.

Abstract: Methods and compositions are provided for the diagnosis of allergen hypersensitivity in a patient. Rare, allergen-specific cells are enriched from a complex cell population, e.g. a patient blood sample. The percentage of blood cells that bind to a particular allergen is less than 0.01%. The allergen-specific cell population is enriched by magnetic cell sorting. In normal blood, the allergen-binding cells are primarily B-cells expressing CD19 and CD21. In blood from allergic patients, an additional population of effector cells, e.g. basophilic granulocytes is labeled by the allergen.

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: The assay described herein is predicated on an observation that when acridinium ester labeled tracers are bound to their corresponding binding conjugate immobilized on a metal oxide solid phase, the measurable chemiluminescent light emission of the labeled tracer bound to the solid phase is quenched as compared to the free fraction tracer that is unattached to the solid phase. According to the invention, a non-separation specific binding assay to detect or quantify the presence of an analyte is provided where the entire reaction mixture is flashed (including unreacted tracer) and modulated signal (because of the quench effect) is associated with a reference, thus determining the amount or presence of said analyte in said sample. Disadvantages inherent in heterogeneous assays employing multiple separations may be avoided using this non-separation method.

Abstract: An immunoassay directed at certain analytes that are polyaromatic hydrocarbons, such that the immunoreactive standard used for assay calibration allows the creation of calibration solutions of superior stability.

Abstract: A magnetic separator device is provided for separating biological materials from carrier fluids using the technique of high gradient magnetic separation. A release compensator reduces the amount of force that an operator needs to apply in order to remove a separation column from the magnetic field of the separator device. The release compensator may be a mechanical compensator, but is preferably a magnetic compensator. The magnetic separator device also preferably includes a mount for mounting the device to a wall. The mount is preferably a pair of additional magnets.

Abstract: An apparatus for immunoassay using a 96-well microplate includes a mechanism for supporting the microplate in a relatively fixed position, a magnetic microplate assembly containing multiple cylindrical magnets positioned in 4.times.6 arrays for insertion from the bottom of the microplate in the spaces between the wells of the microplate, and a device for moving the magnet microplate assembly relative to the microplate thereby to permit selective separation of magnetic components within the microplate wells. The magnets, preferably cylindrical in configuration, are placed between groups of four wells in the microplate. The magnetic microplate assembly is reusable. The magnets do not come into contact with any of the fluids within the wells of the microplate.

Abstract: Gelatin and aminodextran coated polymer core particles useful in immunoassays and methods of making the same are disclosed. The preparation of aminodextrans having varying amounts of amine groups is also described, as is a method of crosslinking gelatin and aminodextran without the use of a stabilizer.

Abstract: Assays for separating magnetic particles include separating magnetically responsive particles from a liquid dispersion disposed in a plurality of reaction vessels, and transporting the reaction vessels in sequence past at least one processing position. A robotics reagent arm and probe dispense reagents into the reaction vessels and a reaction monitoring device is capable of relative movement with respect to the transporting device. Incomplete separation is effected by positioning a magnetic field in contact with the reaction vessel for a first shortened time interval during which the particles partially aggregate and afterwards are removed from the reaction vessel. The magnet is repositioned in contact with the reaction vessel for a third time interval to achieve full separation of particles from the liquid.

Abstract: A method of flow cytometric analysis of leukocyte subpopulations using a fluorescence trigger and gating on light scatter vs. fluorescence. The methods are useful where light scatter parameters are unsatisfactory for identification of leukocyte subpopulations, for example when analyzing lysed blood samples without removal of lysing reagent or unbound label prior to analysis.

Abstract: This invention relates to magnetic particles comprising mixed oxides of divalent metals and iron (III), having a diameter of 1-10 nm and a surface area of 120-350 m.sup.2 /g, with silanes bound to the surface of said particle. It also relates to (1) the process for making said particles by simultaneous precipitation and silanization from aqueous solution and (2) their use as carrier materials for the magnetic separation of substances immobilized therewith.

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 method for measuring the responses of sets or subsets of lymphocytes to mitogens or antigens in a sample is disclosed comprising incubating a population of cells with a mitogen or antigen, separating the desired subset of cells by means of the interaction of a specific binding reagent that is attached to the solid phase with a cell surface determinant that is present on the cell subset of interest, lysing the separated cells, and measuring an intracellular component that is increased if the cells have responded to the stimulus. The method provides a convenient, simple, and reliable method for measuring immune function in a variety of conditions.

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: Methods are disclosed for separating a component of interest from a mixture containing the component of interest and other components. The method comprises contacting a first liquid medium containing the component of interest and other components with a second liquid medium that is of different density than and/or of different viscosity than the first liquid medium. The contact is carried out in such a way that mixing of the media is minimized or avoided. The component of interest is bound to magnetic particles. The contacted first liquid medium and second liquid medium are subjected to a magnetic field gradient to allow the magnetic particles to migrate into the second liquid medium and separation of the component of interest from other components is realized. Also disclosed are assays employing the present method. Kits for carrying out the present method and assays are also disclosed.

Abstract: A method for interfering with the binding between p53 and MDM2 or a protein having a p53 binding site analogous to that of MDM2, which method comprises administering a effective amount of a compound, selected from the group consisting of a peptide having up to twenty eight amino acids which is able to disrupt or prevent binding between p53 and MDM2, or a functional peptide analogue thereof.Compounds for use in the method, methods for detecting such compounds and their application in the diagnosis and treatment of tumours is also described and claimed.

Abstract: A method and apparatus for separating solid supports formed of magnetic particles on which immunocomplexes are bound, from a liquid phase includes a reaction container containing a fluid in which magnetic particles having immunocomplex bound thereon are suspended. The reaction container is positioned at a flock forming station, where the fluid is subjected to an alternate current magnetic field having a temporally varying intensity by an electromagnetic. The magnetic particles are flocculated with each other due to the application of such varying magnetic field to form a multiplicity of flocks. A stronger magnetic field then is applied to the resulting contents in the reaction container by a permanent magnet. The flocks are magnetically fixed on the inner wall surface of the reaction container by the action of the stronger magnetic field.

Abstract: The present invention provides labeled synthetic libraries of random oligomers and methods and apparatus for generating labeled synthetic oligomer libraries. Each member of such a library is labeled with a unique identifier tag that specifies the structure or sequence of the oligomer. In a preferred embodiment of the present invention the identifier tag is a microchip that is pre-encoded or encodable with information that is related back to a detector when the identifier tag is pulsed with electromagnetic radiation.

Abstract: Antibodies made to a flanking region GPR(31-98) in human gastrin-releasing peptide (GRP) precursor. Since the antibodies have high affinity to GRP precursor, and the GPR precursor is highly stable in the blood, then lung cancer, especially small cell lung cancer can be diagnosed with high reliability by detecting or measuring GRP precursor in the blood of a patient using the present antibodies.

Abstract: Red blood cells are removed from whole blood or a fraction thereof by agglutinating whole blood with a mixture of a free agglutinating agent and nucleating particles having agglutinating agent intimately associated therewith to form clusters of red blood cells. High molecular weight polyethylene glycol may be added further to enhance agglutination. The clusters of red blood cells are much larger than the size of individual red blood cells, so that the clusters can easily be filtered through a porous medium. The plasma, which is substantially free of red blood cells, is further passed through a filter that optionally contains an additional agglutinating agent. Flow-delay additives may be provided to retain the fluid sample in contact with a reagent for a predetermined time.

Abstract: The present invention provides a method of linking a target particle to an insoluble support, wherein said particle is bound support by means of a specific binding partner, characterized in that the linkage between said binding partner and said support comprises hydroxyboryl/cis-diol bond. The invention has particular utility in the immobilization and isolation of cells.

Abstract: This invention relates to a combinatorial process for synthesizing a library of azetidinone peptide-like compounds. The compounds are synthesized as mixtures from a common azetidinone intermediate. The compounds are biologically active as inhibitors of the Vasopressin (V1a) receptor.

Abstract: The invention provides a method for both the positive and negative selection of at least one mammalian cell population from a mixture of cell populations utilizing a magnetically stabilized fluidized bed. One desirable application of this method is the separation and purification of hematopoietic cells. Target cell populations include human stem cells.

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: An immunodiagnostic reagent consists of magnetic balls covered with a substance binding specifically to a substance to be detected in suspension in a suitable liquid. The magnetic balls consist of an organic matrix enclosing a magnetic charge and having a magnetizable material mass/non-magnetizable material mass ratio between 60 and 70%.

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: Magnetic porous inorganic siliceous materials having a particle size of about 1 to about 200 microns useful as solid supports in various chromatography, immunoassays, synthesis and other separation and purification procedures is disclosed.

Abstract: A cuvette based testing device for use in testing or otherwise analyzing a fluid sample. A cuvette is provided that defines at least one conduit, wherein the fluid sample is introduced into the various conduits. Reagents are disposed within the conduits that are intended to be mixed with the fluid sample. The fluid sample is drawn into the conduits by the force of a pneumatic pump. As the fluid sample contacts the various reagents, the reagents mix with the sample. Mixing is further conducted by moving the fluid sample back and forth across an obstruction in the conduit. The obstruction causes turbulent flow in the fluid sample, thereby mixing the sample with any reagent also present. The conduit is preferably transparent. The fluid sample is brought to a point in the cuvette where it is disposed below a detector. The detector is used to measure a characteristic of the fluid sample such as optical density, nephelometry, fluorescence, chemical luminescence, photoemittions or the like.

Abstract: The invention is a device and a method for collecting samples mixing the samples with test reagents, and acting as a container in which the mixture can be incubated and the test reaction viewed by microscope or imaging device. This device enables an entire test to be performed in one simple step without complicated handling procedures. The device consists of a cartridge with a well with micro-lances imbedded in the bottom of the well and an overlying micro-baggy containing a mixture of reagents. There are two reagents present in the micro-baggy: the first consisting of antibodies coupled to paramagnetic microspheres and the second consisting of antibodies coupled with a fluorochrome. A test subject presses down onto the micro-baggy and at the same time punctures his/her finger or thumb on the micro-lances. Once the finger has been lanced, breaking the micro-baggy, the reagents mix with the test subject's blood. The well is then covered by a clear mylar strip.

Abstract: Disclosed and claimed are methods and apparatus for performing a binding assay for an analyte of interest present in a sample based upon measurement of electrochemiluminescence at an electrode. The method uses magnetically responsive particles. The method and apparatus call for a plurality of electromagnets or permanent magnets in north-south orientation for imposing a magnetic field so as to collect the particles.

Abstract: The invention relates to an improved method for the manufacture of magnetically responsive particles, also called ferrofluids. The improved method involves a heat treatment step, which may occur at various times during the preparation of the materials, including during subdivision of the magnetic starting material, during the addion of a coating material, after formation of a magnetically responsive particle, or some combination thereof. The materials formed by such a process have numerous advantages over materials formed by other processes, including enhanced salt stability, increased coating uptake, and increased binding capacity. These ferrofluids have applications in a variety of preparative and diagnostic techniques, including immunoassay, cell separations, toxicity testing, food testing, environmental analysis, and MRI.

Abstract: The invention relates to a method of measuring antigens or antibodies in biological fluids in appropriately designed reaction cells in an automated analytical apparatus. The method includes the steps of contacting, in the reaction cell, the biological fluid with antibodies specific for a desired analyte antigen, which antibodies are coated on magnetic particulate carrier, under conditions such that binding of the antibody to the desired analyte antigen occurs, and detecting the presence or absence of an immunocomplex formed between the antibody and the desired analyte antigen. The automated analytical apparatus includes a closed circuit transfer path having means for transferring cells around the entire transfer path, and a thermostating period for each analysis to be performed with the automated analytical apparatus. The transfer path includes a loading station, a reagent delivery station, a mixing and washing station, a separating station and a discharging station.

Abstract: Improvements in the existing procedures and materials for conduct of high gradient magnetic separation (HGMS) are disclosed. Superior superparamagnetic particles, optionally coated with a polysaccharide or other, usually organic, materials can be prepared in uniform compositions with homogeneous magnetizations. The coating can conveniently be conjugated to a specific binding moiety complementary to a biological material whose purification or separation is desired. In addition, plastic coated matrices which form superior magnetic gradient-intensifying supports are disclosed, along with improved methods and apparatus to conduct HGMS.

Abstract: Improved magnetic separators, devices and methods for magnetic separation procedures are provided. The improved separation devices contain matrices which provide uniform pores or channels that reduce the entrapment of air or non-target substances, and decrease the loss of target substances due to mechanical disruption. Target cells, from various systems and organs, or other target biological substances are labeled in conjunction with a suitable specific binding member, and isolated using the devices and methods of the present invention. In its simplest form, the cell separation system of the present invention has two main components: a magnetic separator and a cell separation reagent. A more complex separation device includes fluid passages, collection and storage containers and the separation column. The fluid circuitry can be constructed with integrated valves, or the valves may be applied externally to the fluid pathways.

Abstract: The invention provides an apparatus for performing a process for amplification of specific nucleic acid sequences based upon the separation of nucleic acid strands by an electromagnetic field. This means of separation allows the use of mesophilic polymerases in the amplification process, thereby increasing the speed and fidelity of the amplification process, as well as the size of target nucleic acid that can be amplified.

Abstract: An improved cell separator is provided that includes apparatus for automatically controlling the cell separation process. Particularly, a plurality of valves are responsive to a data processor assembly for controlling the path of fluid flow through the cell separator. A plurality of sensors are provided for providing sensor signals indicative of the density of fluid flowing through the cell separator. The microprocessor is responsive to the sensor signals for controlling the flow and operation of the cell separator. A parastaltic pump is responsive to the microprocessor assembly for controlling the speed and direction of fluid flow through the system. A stirplate assembly is responsive to a drive signal from the data processor assembly for controllably agitating the contents of a column. The data processor assembly is further responsive to the sensor input to provide the valve control signals and pump control signal to control the concentration of selected cells that are collected.

Abstract: This invention is directed to a ligand-receptor assay for determining the presence of at least one target ligand, capable of competing with a ligand analogue conjugate for binding sites available on a ligand receptor, said ligand analogue conjugate comprising at least one ligand analogue coupled to a colloidal gold particle, in a fluid sample suspected of containing said target ligand comprising the steps of:a. contacting said fluid sample with said ligand analogue conjugate and said ligand receptor to form a homogeneous reaction mixture, the relative amounts of said ligand analogue conjugate and said ligand receptor being selected such that in the absence of said target ligand and subsequent to substantially equilibrium binding in said reaction mixture, substantially all of said ligand analogue conjugate is bound to said ligand receptor such that no unbound ligand analogue conjugate is detected as a result of the assay method;b.

Abstract: A method is described for performing an affinity assay comprising contacting a sample to be assayed for the presence of an analyte with a dry reagent containing the analyte (hapten, antigen, antibody, receptor, or complementary polynucleotide) bound to a reaction cascade initiator, an antibody or other binding pair partner reactive with said analyte, and magnetic particles, to form an assay mixture in a reaction chamber, incubating the assay mixture, applying an oscillating or moving static magnetic field to the assay mixture, activating the reaction cascade initiator to initiate a reaction cascade, monitoring the response of the magnetic particles to the oscillating or moving static magnetic field to provide a time varying signal, and determining the analyte concentration of the sample by analysis of the time varying signal, as well as a kit for performing the assay and a diagnostic system for performing the assay.

Abstract: The invention relates to magnetic protein conjugates of the formula I ##STR1## in which M represents a dispersible magnetically reacting material or particle which carries aminogroups, Ig represents a protein which carries one or more mercapto groups, and X represents an organic chemical structure which links the two ligands by chemical means, to a process for the preparation of protein conjugates of the formula I, and to the use of conjugates of this type for removing cells or soluble bioorganic molecules or components from aqueous salt solutions or body fluids, and to the use thereof within the framework of a diagnostic method or as a diagnostic aid.

Abstract: The present invention provides a new analytical method that an antigen, an antibody or a nucleic acid can be assayed at a high sensitivity in the immunoassay.The present invention provides a method for assaying a substance which comprises the steps of (a) reacting an antigen, an antibody or a nucleic acid which is the substance to be measured with an antibody, an antigen or a nucleic acid to which a polyacridinium compound is bound and which can be bound to the substance to be measured, (b) carrying out a luminescence treatment, and (c) measuring the luminescent intensity of the reaction solution.

Abstract: A method of recovering a first material, e.g. plasmid DNA, from a solution containing pre-precipitated second material, e.g. genomic DNA and cellular debris, by precipitating the first material in the presence of magnetically attractable beads which become non-specifically associated with the newly formed precipitate, using a magnet to draw down the beads and the newly formed precipitate, and removing the supernatant.

Abstract: A method for determining the presence and/or concentration of a target substance e.g. protein, nucleic acid, bioparticle etc. in a fluid sample is provided. The method disclosed combines elements of immunoassays, coated cup assays and magnetic particle separation to effect the quantitation and recovery of an analyte in solution. Also the method ensures the non-reorientation of magnetically collected material by linking the magnetic particles to a collection surface via a specific binding pair. This linkage immobilizes the magnetic-analyte-containing material and thus allows for vigorous washing and reagent addition without significant redistribution or displacement. Thus the assay of this invention offers the speed of diffusion controlled kinetics as in a ferrofluid assay, the speed of collection of labeled target substance as in a magnetic assay as well as the ability to magnetically monolayer the ferrofluid, all of which is combined with the ease of washing and signal detection found in a coated cup assay.

Abstract: Red blood cells are removed from whole blood or a fraction thereof by contacting whole blood with a combination of an agglutinating agent and nucleating particles to form clusters of red blood cells. High molecular weight polyethylene glycol may be added further to enhance agglutination. The clusters of red blood cells are much larger than the size of individual red blood cells, so that the clusters can easily be filtered through a porous medium. The plasma which is substantially free of red blood cells is further passed through a filter that optionally contains an additional agglutinating agent. Flow-delay means may be provided to return the fluid sample in contact with a regard for a predetermined time.

Abstract: The invention relates to the use of collagen as solid binding substrate for a sensor called ligand or refining agent, capable of reacting specifically with an element to be detected in a biological medium, to form a specific complex.Preferably, the solid substrate comprises atelocollagen or a mixture of atelocollagen and of polyholoside.The invention thus makes it possible to provide a biological reactant of high specificity and of which the constituents are of natural origin. It can be used easily and quickly.

Abstract: A method for separation of a mixture of biological entities into at least three distinct, subpopulations. Different antibodies are provided, with each antibody bound to a solid support in a unique manner such that by a manipulation of the physical or chemical environment, the bonds between the antibodies and the solid supports can be selectively broken. The mixed population of cells is incubated with the antibodies. The cells are magnetically separated from a test medium and collected in a monolayer upon a collection surface. Then by manipulation of the physicochemical environment, specific linkages can be broken and desired cell subpopulations released from the collection surface. This method has medically significant diagnostic and therapeutic applications, as entire cell types can be separated from non-malignant medically vital cell types. Cancer can be diagnosed, staged, and monitored. Genetic analysis from maternal blood, CVS, or amniocentesis samples is possible.

Abstract: The present invention is a sample preparation system and method that can be used with all types of analyte materials, that produces homogeneously deposited crystals across a sample surface, and that lends itself to automation. In this system and method, analyte crystallization is caused by lyophilization. A homogeneous analyte/solvent mixture is placed on a sample surface. The mixture is frozen, then the solvent is sublimated through the application of a vacuum. A homogenous distribution of analyte crystals across the sample surface results.

Abstract: A method of marking a liquid and subsequently detecting that the liquid has been marked, which method comprises: adding to the liquid an additive comprising a plurality of particles in an amount no greater than 1 part weight of particles per 10.sup.6 parts weight liquid, the particles comprising signal means to aid their detection and not being visible in the liquid to the naked eye; sampling a portion of the liquid containing said additive, and detecting the presence of particles in the liquid, with the proviso that said signal means does not consist solely of a nucleic acid tag.

Abstract: Gelatin and aminodextran coated polymer core particles useful in immunoassays and methods of making the same are disclosed. The preparation of aminodextrans having varying amounts of amine groups is also described, as is a method of crosslinking gelatin and aminodextran without the use of a stabilizer.

Abstract: An aqueous colloidal dispersion for diagnostic or immunodiagnostic tests, comprising non-polymer nuclei surrounded by a hydrophilic copolymer that contains functional groups, a method for the detection of a specifically binding substance or immunochemically active component in a test fluid, and test kit containing the aqueous colloidal dispersion.

Abstract: A method for verifying that an assay methodology is properly performed, that assay reagents employed possess the necessary potency for accurately performing such assay methodology, and whether or not test samples or assay reagents have been tampered with or are adulterated, is described. The method is performed by employing an assay verification sample, comprising a positive analyte component and the test sample under analysis, wherein the assay verification sample is analyzed employing the same assay reagents and essentially the same assay methodology employed to analyze the test sample. The method is particularly useful for performing heterogeneous immunoassays on an automated continuous and random access analytical system.