Abstract: The present invention concerns a method for separating at least one species of biological entities from a sample solution, by contacting the sample with a matrix of magnetic particles formed on a substrate such as a sheet a gel, etc. The particles in the matrix are coupled to entities capable of specifically binding to the species of biological entities to be separated. The separation is carried out either for detection purposes for obtaining separately each species of biological entities or for synthesis purposes. The invention further concerns matrices of magnetic particles formed on various substrates and kits for use in the method.

Abstract: Assay methods utilizing the response of a magnetically responsive reagent to the influence of a magnetic field to qualitatively or quantitatively measure binding between specific binding pair members. According to the invention, the presence of an analyte mediates whether or not the magnetically responsive reagent binds to a mobile solid phase reagent. The extent of binding will modulate the response of the magnetically responsive reagent or that of the mobile solid phase reagent, or both, to the influence of a magnetic field. Hence, by measuring the response to the magnetic field of the magnetically responsive reagent, or that of the mobile solid phase reagent, the presence or amount of analyte contained in a test sample can accurately be determined. The invention utilizes various devices to carry out the assay methods described.

Abstract: An improved homogeneous enzyme immunoassay process for quantitatively analyzing an antigen by determining the change in the enzymatic activity caused by a reaction between the antigen and an enzyme-labeled antibody. The antigen is reacted with an enzyme-labeled antibody, followed by the reaction with a second antibody capable of recognizing and binding to a different epitope and then with a third antibody capable of recognizing and binding to the second antibody. The enzymatic activity of the labeling enzyme is determined by a water-insoluble substrate. Using the water-insoluble substrate, steric hindrance is enhanced. A highly-sensitive analysis can be carried out by a simple operation even when the antigen has a molecular weight falling within an intermediate range, for example, a range of M.W. 10,000 to 70,000.

Abstract: Surface regeneration of affinity biosensors and characterization of biomolecules associated therewith by multivariate technique employing cocktails of regeneration agents to optimize regeneration of biosensor surface and/or characterize biomolecules associated therewith. Kits and stock solutions for use in the context of this invention, as well as associated computer algorithms are also disclosed.

Abstract: Calibrating an immunoassay by generating two reaction rate measuring curves, from samples having higher and lower relative levels of antigen, extrapolating a combination of the curves to cover sample concentrations known to contain an excess of antigen relative to an amount of capture reagent and combining the low end linear potion of the higher reaction rate measuring curve with the higher end portion of the extrapolated reaction rate measuring curve, thereby eliminating measuring inaccuracies otherwise arising from the hook effect. For antigen concentrations higher than the assay range, a high antigen signal utilizing the two rates avoids reporting false results.

Abstract: The present invention relates to an assay for the detection of modified nucleoside levels in a patient. Detection of the modified nucleoside levels in a patient having a disease such as cancer allows for the progression of the disease to be followed and therapeutic regimens to be altered. Such an assay is particularly useful in following the response of cancer patients to chemotherapeutic treatment.

Abstract: A method is disclosed for the rapid diagnosis of disorders characterized by an ischemic event, such as stroke, transient ischemic attack, head trauma, myocardial infarction or other insults resulting in interrupted cranial blood flow. The method involves detection of the presence of the gamma isoform of protein kinase C (PKCg) in peripheral blood, which signals damage to central nervous system tissue and at least transient breakdown of the blood brain barrier. The assay may be performed, e.g., by emergency medical personnel, in a time frame that allows treatment of the patient before permanent damage to the central nervous system occurs.

Abstract: The present invention is directed to an Assay for high capacity screening of substances interfering with the attachment of human IgE to its high affinity receptor and/or of substances capable of detaching already bound IgE from this receptor and for the differential analysis between autoimmune disorders and classical allergies.

Abstract: Homogeneous assays for determining quantitatively the extent of a specific binding reaction can be carried out effectively on very dilute solutions using measurements of fluorescence if a fluorescence measurement scheme that is capable of rejecting short-lived background fluorescence is employed and if the fluorescent group being measured has the following properties: a. the group being measured must be a rare earth metal chelate complex combination; b. the chelate must be water-soluble; c. the complex combination must also be stable in extremely dilute aqueous solutions, that is, the measured chelate must have at least one ligand having a metal-to-ligand binding constant of at least about 1013M−1 or greater and it must have a fluorescent emission that is long-lived compared to the longest decay lifetime of ambient substances and have a half life of from 0.01 to 50 msec.

Abstract: A new class of cellular receptors extensively homologous but not identical to coagulation factors V and VIII is identified. These new cell surface receptors are designated effector cell protease receptors (EPRs) and include EPR-1, which is shown to bind protease ligands. The DNA and amino acid residue sequences of the receptor are also described. The invention also discloses methods, sequences and vectors useful in the purification and synthesis of cellular receptors of the present invention. Antibody compositions capable of immunoreacting with the receptor or with polypeptides containing the identified amino acid residue sequences and related therapeutic and diagnostic protocols are also described, as are polypeptides, compositions and methods relating to the inhibition of T lymphocyte proliferation using the antibodies disclosed herein. The receptors are also demonstrated to bind coagulation factor Xa, which binding is inhibited by various disclosed monoclonal antibodies to the receptors.

Abstract: Formed constituents of a quiescent anticoagulated whole blood sample are optically or visually analyzed in a sample chamber which has a varying through plane thickness due to convergent opposing sample chamber walls. At least one of the convergent walls of the chamber is transparent so that the blood sample constituents can be observed. The chamber's varying thickness produces a first lesser thickness region in the chamber wherein a quiescent monolayer of red blood cells in the sample will reside after the sample is introduced into and fills the chamber. Larger formed constituents such as white blood cells in the sample are unable to enter the aforesaid lesser thickness region of the chamber. The red cells which reside in the greater thickness regions will agglomerate to form rouleaux and lacunea. The exact thickness of the chamber at any particular location in the chamber can be predetermined, or can be determined in situ as the sample is being analyzed.

Abstract: A method for detecting an analyte of interest present in a mixture at an ultralow concentration includes selecting a radioactive derivatizing agent comprising a multiphoton-emitting radioisotope moiety and a moiety reactive with the analyte of interest, the radioisotope moeity being bound to the derivatizing agent by a bond that is stable under the conditions employed in the other steps of the method, derivatizing the analyte of interest with the derivatizing agent, separating the analyte of interest from other components of the mixture by chromatography, and detecting the analyte of interest using multiphoton detection. The derivatizing step may be performed before or after fractionation. A radiophore for multiphoton emission enhanced chromatography has a first moeity bound to a multiphoton-emitting radioisotope, and a second moiety that is reactive with a functional group of an analyte of interest.

Abstract: A separation method, a method for detection, a sensor, and a test-kit find application in immunological detection. The separation method provides for separation of a primary species which separation method is suitable for use in an immunoassay method for the detection of an analyte species and includes the use of a first auxiliary species capable of being formed into a second auxiliary species which second auxiliary species is capable of interacting with a third species to facilitate separation.

Abstract: An enzyme-labeled immunoassay is performed by the steps of allowing a test sample to react with an enzyme-labeled reagent, allowing a substrate to react with the enzyme to form a signal, and immobilising the enzyme-labeled reagent, with the prevention of a further signal formation from a predetermined time on after the immobilisation of the enzyme-labeled reagent, using an enzyme inhibitor.

Abstract: This invention relates to a spin filter assembly and its usage to facilitate the isolation and analyses of molecules and compounds such as proteins present in various biological and non-biological solutions. The spin filter assembly of this invention comprise of a tube having an open top end, a bottom end opposite the open top end, a body of a first length, an inner diameter and a first outer diameter, a filter means at the bottom end, the tube insertable to an upper portion of a centrifuge holder having a closed lower end, an open upper end, a length longer than the first length of the tube, and a second inner diameter greater than the first outer diameter of the tube; and, a container closure means that fits on top of the open end of the tube. The spin filter assembly can be a component of a sample preparation or assay kit, for example, a kit for analyzing proteins by immunoprecipitation. A process for analyzing proteins by immunoprecipitation using the spin filter assembly is described.

Abstract: The invention concerns a solid-phase determination method and equipment and an adapter for use in these. In the method a sample is allowed to react with a separating reagent bound to the outer surface of a separate solid phase body, whereafter the body is removed from the vessel and is taken to a measurement vessel, if required through one or several intermediate step vessels. At least one vessel contains a medium needed in a determination step to be performed therein when the phase body is brought into this vessel. The invention is especially suitable for use in automatic immunodetermination systems.

Abstract: Disclosed is a method for determining the concentration of an analyte in a fluid test medium by use of an immunochromatographic test strip through which the test fluid can flow by capillarity. The test strip has at least two capture bands and optionally one or more collection bands which capture labeled anti-analyte antibody to provide a detectable signal. The signals from the label is quantitatively detected in each of the bands to provide a pattern of signals which is unique to the concentration of analyte in the test fluid. The pattern of signals are mathematically combined to create a monotonous dose-response curve to thereby factor out the high analyte hook effect which can be present in this type of assay.

Abstract: The invention relates to a method for detecting specific target-cells in a simple and time saving way, using paramagnetic particles, antibodies recognizing the Fc portions of target-cell associating antibodies and target-cell associating antibodies directed to specific antigen determinants in the target-cell membranes. Incubation of the cell suspension with a mild detergent and/or second set of antibodies or antibody fragments, prelabeled or not with fluorescent agents, metallocolloids, radioisotopes, biotincomplexes or certain enzymes allowing visualization, with dramatically increase the specificity of the method. The method can further be used for isolation of the target-cells by magnetic field application and kit for performing the method according to the invention is described.

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

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

Abstract: The invention relates in part to methods and compositions for identifying the presence, measuring the amount, stabilizing, and facilitating recovery of troponin complexes or individual troponin isoforms in a sample.

Abstract: A method for increasing the percentage of mammalian offspring of either sex which comprises contacting a semen sample with an antibody specific for the spermatozoa determinative of one sex and separating said spermatozoa from spermatozoa determinative of the other sex, said antibody being bound to a non-porous magnetic bead support having a diameter of 0.1 to 2 microns.

Abstract: The present invention provides methods for the simultaneous measurement of triiodothyronine (T.sub.3) and thyroxine (T.sub.4) in biological fluids such as serum by direct equilibrium dialysis and immunoassay. Specifically, the method comprises dialyzing the serum sample to equilibrium in a physiological buffer system so that the free T.sub.3 and the free T.sub.4 are separated from T.sub.3 and T.sub.4 bound to serum proteins. The method further comprises combining a measured quantity of the dialyzed serum sample having free T.sub.3 and free T.sub.4 with reagents comprising a measured quantity of T.sub.3 labelled with a detectable marker and a measured quantity of T.sub.4 labelled with a detectable marker; an anti-T.sub.3 antibody of sufficient specificity and in sufficient quantity to bind a measurable quantity of the free T.sub.3, and an anti-T.sub.4 antibody of sufficient specificity and in sufficient quantity to bind a measurable quantity of the free T.sub.4.

Abstract: The invention relates to a process for producing ferrofluid-forming magnetic particles substituted by DMSA (FFSH) that can be covalently coupled, directly or through a difunctional reactant, to an effector, which process comprises combining DMSA with ferrofluid-forming magnetic particles to form FFSS particles having disulfide bonds, and reducing the disulfide bonds of the FFSS at basic pH to form FFSH. The invention includes a composition comprising such FFSH magnetic particles. The invention also relates to a method in which FFSH magnetic particles are incubated with an effector comprising at least one functional group which forms an S--S, C--S, C--C, or C--N bond with DMSA, so that a covalent effector-FFSH complex is formed. The invention further includes a method for separating and/or distinguishing between molecules or cells having a ligand that forms an affinity complex with an effector-FFSH particle of the invention, and those molecules or cells that do not have such a ligand.

Abstract: The present invention is directed to a method of determining the ratio of the concentration or amounts of two or more chemical compounds and/or biopolymers, or of the relative amounts of sub-populations of closely structurally related compounds, in a multi-component mixture, extract, system, and the like using an analytical physicochemical process. The method is based on distribution of the components of the mixture (system, extract, etc.) between two or more immiscible phases and the subsequent determination of the total amounts (concentrations) of biopolymers (chemical compounds) or of the amounts (concentrations) of one or more component(s) or sub-populations of the system in the phases. The ratio between these concentrations is defined therein as the partition coefficient. The partition coefficient is used as a measure of the ratio of the amounts of two or more biopolymers (chemical compounds) or their sub-populations in a multi-component mixture (extract, system, etc.

Abstract: Novel magnetic assay methods and systems, as well as systems for conducting spectrophotometric analysis therewith. According to a preferred embodiment, the magnetic assay methods and systems incorporate a chromatographic medium, such as an assay test strip, that is designed to be contacted with a test solution having activated magnetic particles. A magnetic field, generated by a magnet or electromagnet, is additionally provided that if selectively applied to a chromatographic medium which causes the charged particles to become substantially bound at a site all in the chromatographic medium specified by the position of the magnets, to thus form a captured line or zone. To the degree of magnetic force applied to the medium may be selectively adjusted to vary the width or surface area of the capture line or zone. Additionally, in a preferred embodiment, capture lines may be formed while test strips are in motion along a stationary magnetized rail.

Abstract: Helicobacter pylori is known to cause or be a cofactor in type B gastritis, peptic ulcers, and gastric tumors. In both developed and developing countries, a high percentage of people are infected with this bacterium. The present invention relates generally to certain H. pylori proteins, to the genes which express these proteins, and to the use of these proteins for diagnostic and vaccine applications. Specifically, molecular cloning, nucteotide, and amino acid sequences for the H. pylori cytotoxin (CT), the "Cytotoxin Associated Immunodominant" (CAI) antigen, and the heat shock protein (hsp60). are described herein.

Abstract: A method of determining the concentration of a sample antigen in the presence of an interferant by(1) running two immunoassays on the sample: one assay where the interferant influences the binding of both the sample antigen and a labeled antigen and a second assay where the interferant influences the binding of the sample antigen but not the labeled antigen;(2) obtaining a plot of the possible sample antigen concentrations versus the possible interferant concentrations corresponding to the readout for the sample for each of the two immunoassays; and(3) determining the sample antigen concentration and the interferant concentration which correspond to the point that appears in both the immunoassays plots.

Abstract: The invention relates to the detection of target nucleic acids or nucleic acid units in a sample, by obtaining a SER(R)S spectrum for a SER(R)S-active complex containing, or derived directly from, the target. The complex includes at least a SER(R)S-active label, and optionally a target binding species containing a nucleic acid or nucleic acid unit. In this detection method, the concentration of the target present in the SER(R)S-active complex, or of the nucleic acid or unit contained in the target binding species in the SER(R)S-active complex, is no higher than 10.sup.-10 moles per liter. Additionally or alternatively, one or more of the following features may be used with the method: i) the introduction of a polyamine; ii) modification of the target, and/or of the nucleic acid or nucleic acid unit contained in the target binding species, in a manner that promotes or facilitates its chemi-sorption onto a SER(R)S-active surface; iii) inclusion of a chemi-sorptive functional group in the SER(R)S-active label.

Abstract: The invention provides methods for separating bound label from unbound label within an assay mixture, for predispensing assay reactants in self-contained assay vessels, as well as for detecting the presence and/or amount of an analyte within a fluid sample. In addition, a reusable detection vessel for use therein and with specific binding assays in general is disclosed. In the methods, generally an analyte within a sample is detected or measured by forming an assay mixture containing sample, analyte binding components and label, placing the assay mixture in contact with an immisable primary layer, subjecting the assay mixture to conditions that separate the analyte bound with binding components and label from unbound binding components and label, and subsequently detecting bound label.

Abstract: A suspension of inert particles is prepared in an aqueous solution, to which an antibody or an antigen and a carrier-bound antigen or antibody, respectively, are added in any desired order. After centrifuging, the positive, weakly positive, or negative reaction can easily be recognized on the basis of a simple pattern.

Abstract: The present invention concerns methods for masking inhomogeneity of a member of a specific binding pair (sbp) employed in a capillary electroseparation. The method comprises binding the sbp member to synthetic particles that become localized during capillary electroseparation. Also disclosed is one embodiment of the present invention, which is a method for conducting a capillary electroseparation specific binding assay. The method involves the electroseparation of a labeled first member of a specific binding pair that is bound in a complex from labeled first member that is not bound in the complex. The complex comprises the first member and a second member of a specific binding pair. A combination is provided comprising a sample suspected of containing an analyte, a labeled first member of a specific binding pair, and a second member of a specific binding pair under conditions for forming a complex between labeled first member and the second member.

Abstract: A dual particle immunoassay method and kit for detecting analyte in a sample in which the sample to be analyzed, a binding molecule specific for the analyte, and a particle coated with the analyte to be detected or coated with a second binding molecule are reacted and applied to a porous membrane. The competitive immunoassay utilizes an analyte-coated particle, whereas the sandwich immunoassay employs a second binding molecule-coated particle. All of the reagents except for the coated particle are able to pass through the porous membrane. Detectable particles coated with a binding substance that binds to the binding molecule, such as protein A protein G, second antibody reactive to the binding molecule, or a small synthetic affinity ligand, are reacted with coated particles retained on the membrane surface. The detectable particles will pass through the membrane if not complexed with the coated particle.

Abstract: A method of detecting an antibody in a sample using a labelling compound and comprising the steps of mixing a ligand antigen, antibody or hapten bound to biotin with the sample; an antibody directed against the antibody to be detected bound to paramagnetic particles; and a chemiluminescent acridinium compound bound to avidin or streptavidin to form a solid phase complex; separating the solid phase from the liquid phase; and analyzing the separated solid phase for the presence of chemiluminescent complex.

Abstract: The present invention relates to an on-line detection method comprising the on-line coupling of a fractionation and a biochemical detection technique, which method comprises the addition of a controlled amount of an affinity molecule to the effluent of the fractionation step to react with analytes in the effluent, the subsequent addition of a controlled amount of a detectable ligand capable of binding to the affinity molecule, and detection of the affinity molecule/detectable ligand complex.

Abstract: A testing apparatus 10 having an absorbent matrix 12, including a membrane 14 which contains a plurality of counter-ions 16. Chromoionophore (or fluorionophore)s 18 and affinophores 22 compete to carry ions into the membrane 14 and neutralize the charge of the counter-ions 16. Biological recognition molecules 42 bind to a portion of the affinophores 22 and prevent them from entering the membrane 14, thereby allowing more chromoionophore (or fluorionophore)s 18 to enter the membrane 14. The portion of affinophores 22 bound to the biological recognition molecules 42 is inversely proportional to the amount or concentration of analyte 40 occurring within the solution or medium 30. The result of this is that the color of the membrane-covered matrix changes in a manner related to the concentration of the analyte. One application of this apparatus is a strip test for prediction of ovulation.

Abstract: The present invention relates to a process for the determination of an analyte, in which a sample optionally containing the analyte to be determined is brought into contact with a first receptor R1, which has a binding affinity for the analyte, immobilized on a solid phase, and a receptor R2, which likewise has a binding affinity for the analyte, is added and in which furthermore the resulting immune complexes are brought into contact with a binding factor which has a binding affinity for the analyte and for a receptor R3 immobilized on the same or a second solid phase and in which the amount of the analyte bound to the first solid phase or, if present, to the second solid phase is detected in a suitable manner.

Abstract: Subject matter of the invention is a method of binding a biological material to a solid phase by providing a sample liquid containing the biological material in a sample vessel (A) having an inner contour (A17); then a hollow body (C) which has a contour (C12) that matches the inner contour (A17) is introduced into the sample vessel (A) while being closed with respect to the sample vessel by means of a porous matrix (C11); the sample liquid can enter the structural form (C) through the porous matrix (C11). This method is easy to automate and reduces the generation of aerosols.

Abstract: This invention provides a method for preserving cells which comprises the steps of (a) suspending cells in a physiologically-acceptable, isotonic medium; and (b) fixing the cells so suspended at a temperature of less than about 10.degree. C. under sufficiently hypertonic conditions so as to disperse the cells in a single, unagglutinated state, thereby preserving cells. This invention also provides a method for detecting cells separated from a sample which have been preserved according to the aforementioned method. This invention also provides a method for visualizing cells. Also provided is a method for detecting a metabolic process in cells present in a sample. This invention also provides a method for detecting the presence of rare cells in a sample which specifically possess on their surfaces a moiety recognized by a known ligand comprising preserving cells separated from the sample according to the aforementioned method for preserving cells.

Abstract: Antibodies that selectively bind to quadruplex nucleic acids are described. Isolated cells that produce such antibodies, and methods utilizing these antibodies, are also described.

Abstract: Assay methods utilizing the response of a magnetically responsive reagent to the influence of a magnetic field to qualitatively or quantitatively measure binding between specific binding pair members. According to the invention, the presence of an analyte mediates whether or not the magnetically responsive reagent binds to a mobile solid phase reagent. The extent of binding will modulate the response of the magnetically responsive reagent or that of the mobile solid phase reagent, or both, to the influence of a magnetic field. Hence, by measuring the response to the magnetic field of the magnetically responsive reagent, or that of the mobile solid phase reagent, the presence or amount of analyte contained in a test sample can accurately be determined. The invention utilizes various devices to carry out the assay methods described.

Abstract: A process for the preparation of immunogens or diagnostic reagents that mimic an antigen or a pathogenic organism specific to a disease, essentially characterized by the following operations: identification of at least one antibody that reacts with the antigen or pathogenic organism specific to the disease; construction of phage libraries which display on the surface of the capsid oligopeptides, expressed from random sequence oligonucleotidic inserts introduced into a gene coding for a phage capsid protein using genetic manipulation techniques (for example using a plasmid engineered for the purposes of the invention, the genetic map of which is shown in the figure); selection of the phages that display on the surfaces of the capsid antigenic oligopeptides recognized by said antibody; optional use of the selected phages and/or fragments thereof and/or their derivatives for the formulation of diagnostic kits for the specific pathogenic agent, or in general for the diseases, including immunological disorders typ

Abstract: The present invention relates to novel methods and devices for detecting non-complexed prostate specific antigen (free PSA), which is used in conjunction with total PSA tests to identify patients having either benign prostatic diseases (BPD), such as benign prostatic hyperplasia, prostatitis, or glandular atrophy or prostatic adenocarcinoma (CAP). In a biological sample, one can find not only free PSA, but also prsotate specific antigen (PSA) which has formed a complex with .alpha.1-antichymotrypsin (ACT). The present invention removes complexed PSA (PSA-ACT) from a fluid sample, thereby removing any possible interference due to binding of complexed PSA to an allegedly free PSA specific antibody in an immunoassay for free PSA.

Abstract: Magnetic particles are used as the solid phase to carry out immunoassay. In a reaction vessel, the magnetic particles are mixed with a sample containing TSH as an analyte and a labeled antibody. A chemiluminescent label material is bound onto the magnetic particles with an immunoreaction. A fluid including the above mixture is introduced to a chamber inside a flow through cell, the chamber being sized to have a width greater than a depth. The magnetic particles in the fluid are trapped by a magnet so as to be spread in the planar form over a predetermined area within the chamber, while useless materials are discharged outwardly of the chamber. The chamber is then filled with a buffer solution containing an attractant. By applying a voltage to electrodes disposed in the chamber, the label material on the magnetic particles is excited to emit an electro-chemiluminescence. The luminescence is detected by a photomultiplier.

Abstract: An antibody specific for a target analyte is purified by affinity chromatography on a substrate bearing a low-affinity analogue of the target analyte. The antibody is displaced from the substrate by contact with a second analogue of intermediate affinity, which remains complexed with the antibody. This complex can be used in a conventional assay for the target analyte, which displaces the intermediate-affinity analogue. The complexed antibody is rendered more storage-stable because the second analogue protects the antibody binding reagion.

Abstract: A test device, system and method, the device composed of an elongated, toothbrush-shaped, transparent, plastic housing and a lateral-flow test strip for the detection of an analyte, such as a beta-lactam in milk, in the housing, the housing having an expansion cavity to receive expanded, liquid-contacted, absorbing material in the test strip, and to control lateral flow rate and times in the test strip.

Abstract: The invention provides a method for separating target cells from a plurality of cells which is based on a reversible high affinity interaction between two molecules. The method comprises: forming a target cell/cell binding reagent/first molecule/second molecule/solid support complex, wherein the cell binding reagent is specific for target cells present within a plurality of cells and wherein the first molecule reversibly binds to the second molecule; removing non-target cells of the plurality of cells not attached to the solid support; and reversing the first molecule binding to the second molecule, thereby releasing the target cells as separate cells from the plurality of cells.

Abstract: A method of concentrating a disease-related conformation of a protein such as the PrP.sup.Sc in a sample is disclosed. The method comprises liquefying the sample and adding a complexing agent such as phosphotungstic acid (PTA) which complexes preferentially or exclusively with the PrP.sup.Sc. After the complex is formed the composition is centrifuged until the complex settles at the bottom. Thereafter, the supernatant is poured away. The remaining pellet may be resuspended in an aqueous solution containing a protease inhibitor for storage. The PTA stains the PrP.sup.Sc making the resulting concentrated PrP.sup.Sc susceptible to further analysis, making it possible to quickly and efficiently determine the presence of PrP.sup.Sc and its concentration in a sample. The method can be used to render a sample non-infectious by removing all or substantial of the infectious form of a protein from a sample.

Abstract: A fluorescent immunoassay employing the interior surface of a capillary tube is provided. Devices to permit immunoassays using one or more capillary tubes, an apparatus for use with the devices, and a process for screening for analyte in a sample using the devices and apparatus are also provided. Samples suspected of containing analyte are added to a disposable self-contained sample tray containing one or more sample wells, mixed with a reagent, drawn into one or more spaced-apart capillary tubes held within a disposable cartridge connected to an analytical apparatus, reacted with a binding member on the surface of the capillary tube, washed to stop the reaction, and dried by the apparatus. The capillary tube is then exposed to a signal generation device to create a fluorescence signal that is detected using a signal detector. The apparatus determines the presence of the analyte and optionally determines the amount of analyte present in the sample, and presents the results to the operator.

Abstract: The present invention relates to methods for measuring endogenous cytokines in blood. The method accurately measures the cytokines in the blood in the presence of substances that bind the cytokines thereby causing the measurement of the cytokines by conventional methods to give inaccurate results. The present invention also includes the non-invasive measurement of cytokines in biological fluids such as saliva and nasal secretions. Finally, the present invention allows one to monitor the level of cytokines in the blood during treatment of a human or animal with cytokines.