Abstract: A vessel for conducting blood cell agglutination assays is disclosed. A barrier retains reactants in an upper chamber during incubation, then, in response to a force, permits reagents to enter a lower chamber containing a matrix for separating agglutination.

Abstract: Two or more analytes having the same action, or having different actions in spite of their similar structures, or two or more analytes having the same action and the same detectable chemical characteristics, in samples derived from living bodies, etc., can be measured rapidly and easily by forming one or more complexes with one or more affinity substances, separating the complexes by using high pressure liquid chromatography, followed by measurement of the amount of an affinity substance or one of the analytes.

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 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 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: 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 incubating, the mixture is allowed to traverse the absorbent material from the contact portion through the measurement portion of the absorbent material.

Abstract: This invention provides a device and method for preparing a plasma enriched sample for use in an immunoassay strip. All parts that contact blood or a blood fraction remain in a container and prevent contamination from used blood. In one embodiment a sampling device collects blood and enters the container. A plasma enriched sample fills a plasma receptor which in turn is transferred to an immunoassay strip. Plasma is washed out of the strip by an aqueous solution. In another embodiment the sampling device doubles as a plasma separator. The invention allows sensitive and safe immunoassays to be performed on whole blood samples outside of the normal clinical laboratory setting.

Abstract: A device for combined bioaffinity assay and electrophoretic separation is provided, which comprises a capillary system having two stages, a first stage in which bioaffinity interactions of analyte molecules and molecular recognition elements are performed, and a second stage, in which electrophoretic separation of the analyte molecules and subsequent detection of the separated species is accomplished. Within the first capillary stage the molecular recognition elements are attached and immobilized to the inside capillary wall, for example, by adsorption or by covalent binding to the capillary material. The method for combined bioaffinity assay and electrophoretic separation comprises flowing an analyte through a capillary system having two stages. In a first capillary stage the analyte molecules are captured by respective molecular recognition elements present in that stage.

Abstract: The invention is an improved single-step test device for detecting the presence of a pre-selected analyte in a urine stream. The device has a hollow outer casing and an assay material disposed within the casing. The outer casing defines: a urine inlet port; a viewing window; and at least one drainage vent spaced about the urine inlet port. The assay material is a sorptive material defining: a urine sample application region adjacent to, and in fluid communication with the urine inlet port; a capture region adjacent to the viewing window; and a fluid flow path for transporting liquid sample between the urine sample application region and the analyte capture region. The drainage vent is located to permit excess urine entering the casing from the urine stream to exit the casing thereby to minimize hydraulic pressure induced flooding of the assay material disposed within the casing and to reduce the frequency of false test results.

Abstract: The present invention concerns a method and an analytical device for the simultaneous detection of at least two organisms selected from the group consisting of Chlamydia trachomatis (CT), Neisseria gonorrhea (NG), and Mycoplasma (M) from a single specimen.

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: 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: 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: Trace components in samples can be measured rapidly with high precision by applying interaction between an analyte to be measured and an affinity substance and using a membrane having specific separating capability.

Abstract: This invention presents novel assay devices employing capture reagents, involving a specific binding member attached to a charged substance, and porous material containing a capture or reaction zone that is oppositely charged with respect to the charged substance included in the capture reagent. In one embodiment, a test sample suspected of containing the analyte of interest is contacted with the capture reagent to form a charged capture reagent/analyte complex. The complex is then contacted to the oppositely charged capture or reaction zone to attract, attach, and immobilize the capture reagent/analyte complex. With an appropriate indicator reagent, both sandwich and competitive assays can be performed.

Abstract: A chemiluminescent assay method, compositions, kits and chemiluminescent acridan compounds are described which use a two-step chemiluminescent reaction process. The reaction involves an acridan compound, preferably a derivative of an N-alkylacridan-9-carboxylic acid, which undergoes a reaction with a peroxide compound, a peroxidase enzyme and an enhancer under conditions of time, temperature and pH which permit the accumulation of an intermediate compound, which is subsequently induced to produce a burst of light by raising the pH. The result is generation of very high intensity light from the reaction. The peroxidase enzyme is present alone or linked to a member of a specific binding pair in an immunoassay, DNA probe assay or other assay where the hydrolytic enzyme is bound to a reporter molecule. The method is particularly amenable to automated assays because of the separation of the incubation and light generating steps.

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.

Abstract: This invention relates to a cell enumeration immunoassay which uses a calibrated standard, i.e., a substance which behaves like the sample under study and the concentration of which can be correlated to the concentration of the cells. This immunoassay is an efficient alternative to flow cytometry.

Abstract: An analytical test device useful for example in pregnancy testing, comprises a hollow casing (500) constructed of moisture-impervious solid material, such as plastics materials, containing a dry porous carrier (510) which communicates indirectly with the exterior of the casing via a bibulous sample receiving member (506) which protrudes from the casing such that a liquid test sample can be applied to the receiving member and permeate therefrom to the porous carrier, the carrier containing in a first zone a labelled specific binding reagent is freely mobile within the porous carrier when in the moist state, wherein the mobility is facilitated by a material comprising a sugar, in an amount effective to reduce interaction between the test strip and the labelled reagent, and in a second zone spatially distinct from the first zone unlabelled specific binding reagent for the same analyte which unlabelled reagent is permanently immobilised on the carrier material and is therefore not mobile in the moist state, the t

Abstract: Methods of assaying samples for the presence or quantity of an analyte involving immobilization of a gold sol, and optionally an enzyme capable of generating a reaction product, on a solid phase. The gold sol has a mean particle size of less than 20 nm for at least 75% by weight of the particles and is formed into a novel superaggregated complex with at least one protein.

Abstract: Apparatus and method for simultaneously performing at least two assays using certain reagents for a plurality of liquid samples on a continuous analytical system is disclosed. The method comprising the steps of combining an aliquot of each liquid sample with at least one reagent in a first reaction container to form a first assay reaction for each liquid sample, and combining an aliquot of each liquid sample with at least one of the other reagents in a second reaction container to form a second assay reaction for each liquid sample. The method further comprises the steps of incubating the assay reactions of each assay being conducted at least one time, and performing other activities associated with each assay and using the first and second assay reactions to complete each assay, including analyzing the incubated assay reactions.

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.

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: An analytical test device useful for example in pregnancy testing, includes a hollow casing (500) constructed of moisture-impervious solid material, such as plastics materials, containing a dry porous carrier (510) which communicates indirectly with the exterior of the casing via a bibulous sample receiving member (506) which protrudes from the casing such that a liquid test sample can be applied to the receiving member and permeate therefrom to the porous carrier, the carrier containing in a first zone a labelled specific binding reagent is freely mobile within the porous carrier when in the moist state, and in a second zone spatially distinct from the first zone unlabelled specific binding reagent for the same analyte which unlabelled reagent is permanently immobilised on the carrier material and is therefore not mobile in the moist state, the two zones being arranged such that liquid sample applied to the porous carrier can permeate via the first zone into the second zone, and the device incorporating an a

Abstract: A method of dispensing wash solution to separate free from bound labels in a slide immunorate assay. The method comprises dispensing wash first as separate drops spaced to allow complete absorption prior to the next drop, followed by a time at which the rate of dispensed wash exceeds the rate of fluid uptake of the slide, to form a continuous stream. The first phase of this wash method provides a more complete separation of bound from free under the dispense tip than occurs if only a continuous stream is used throughout.

Abstract: Diagnostic and therapeutic compositions which comprise the .alpha.Gal(1-4).beta.Gal subunit are described. These compositions permit the rapid diagnosis and treatment of enteric infections caused by E. coli that produce shiga-like toxins (SLT).

Abstract: A dry-type analytical element for immunoassay having at least one water-permeable layer for measuring a ligand in a sample according to enzyme immunoassay, which comprises,(A) a water-soluble macromolecular substrate, and(B) an enzyme conjugated with antibody reacting with the ligand in the sample capable to act on the above water-soluble macromolecular substrate. The above analytical element further comprises,(C) a macromolecular antigen which is a conjugate of the ligand or its derivative with a macromolecular compound in the above water-permeable layer of the above dry-type analytical element.The invention can conduct highly sensitive and simple enzyme immunoassay.

Abstract: An analytical test device useful for example in pregnancy testing, includes a hollow casing (500) constructed of moisture-impervious solid material, such as plastics materials, containing a dry porous carrier (510) which communicates indirectly with the exterior of the casing via a bibulous sample receiving member (506) which protrudes from the casing such that a liquid test sample can be applied to the receiving member and permeate therefrom to the porous carrier, the carrier containing in a first zone a labelled specific binding reagent is freely mobile within the porous carrier when in the moist state, wherein the mobility is facilitated by a material comprising sugar, in a amount effective to reduce interaction between the test strip and the labelled reagent, and in a second zone spatially distinct from the first zone unlabeled specific binding reagent for the same analyte which unlabelled reagent is permanently immobilized on the carrier material and is therefore not mobile in the moist state, the two zo

Abstract: A method of binding aggregated immunoglobulin or immune complexes comprising contacting them with modified forms of C-reactive protein. The method may be employed for diagnostic and therapeutic purposes and to deplete fluids of aggregated immunoglobulin or immune complexes. Further, a method of reducing the levels of immune complexes in a mammal comprising administering modified-CRP to the mammal, and a method of binding immunoglobulins comprising contacting them with modified C-reactive protein. Also, a method of binding aggregated immunoglobulin or immune complexes comprising contacting them with antibody to neo-CRP, and a method of modifying C-reactive protein. Finally, a test kit for detecting or quantitating immune complexes and a device for removing aggregated immunoglobulin or immune complexes from fluids are disclosed.

Abstract: A chromatographic test strip comprising a solid support having at least a first portion and a second portion with said portions being in the same plane so as to permit capillary flow communication with each other. The sample is added to the first portion. The first portion also may comprise a tracer portion having a tracer movably supported therein. The tracer consists of a visible particulate marker. In the second portion, a binder is immobilized. The test strip is useful in a variety of immunoassays.

Abstract: A homogeneous immunoassay method for the simultaneous determination of one or more antibody, antigen or hapten analytes in a fluid sample, that comprises the quantification of the effect of said analytes on the statistical changes in a dimension of a light scatter pulse height distribution histogram of relatively large diameter monodisperse binding molecule-coated polymeric microspheres induced by the binding to said microspheres of polydisperse binding molecule-coated colloid metal particles of relatively small diameter. For simultaneous assays of multiple analytes, different diameter or refractive index microspheres are assigned to each analyte. The assay may be used in forward binding, displacement, inhibition, and competition type systems, with the direction of the change in histogram dimension depending on the system. A convenient dimension to measure is the normalized peak width of a graphical representation of the histogram.

Abstract: This invention is intended to provide a process by which a complex formed by the interaction between one or more analytes to be measured and affinity substance can be more effectively separated from substances existing together therewith which tend to affect the detection of the complex, for example, free affinity substance, by using high pressure liquid chromatography (HPLC); and a process for measuring a trace component by utilizing said separating process.This invention is characterized in that a substance which has been modified with a substance capable of changing properties of the complex (a separation-improving substance) and has affinity for the complex is attached to the complex. Because of this characteristic, the invention is effective in that the position of elution of said complex in the HPLC can be freely controlled.

Abstract: A method, composition, device, apparatus, and kit for the determination of the presence or amount of an analyte by monitoring an analyte-mediated ligand binding event in a test mixture which contains the analyte to be assayed, a specific binding member, a Raman-active label, and a particulate having a surface capable of inducing a surface-enhanced Raman light scattering. The test mixture is illuminated with a radiation sufficient to cause the Raman-active label in the test mixture to emit a detectable Raman spectrum. The differences in the detected surface-enhanced Raman scattering spectra are dependent upon the amount of the analyte present in the test mixture. Thus, by monitoring these differences, the presence or amount of the analyte are determined.

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

Abstract: A method for detecting multiple subpopulations of analytes of interest in a sample employing a complementary binding moiety to each of said analytes bound to a solid support, wherein each analyte and its complementary binding moiety comprise first and second members of a specific binding pair (msbp) respectively is provided. The method includes the steps of forming a mixture of known proportions of multiple subpopulations of said complementary binding moieties, wherein each subpopulation comprises a different complementary binding moieties, contacting the sample with the mixture so that specific binding pairs are formed on the solid supports, and relating the presence of analytes of interest in the sample to the formation of specific binding pairs associated with each unique proportion of said multiple subpopulations. The method can be performed with solid supports of a single average size and a single fluorochrome and without the need for using three detection systems (fluorescence FS & SS).

Abstract: This invention pertains to methods to detect antibodies in a sample. The methods use an amount of antigen that is up to 1000, preferably 10-100 times the minimum amount antigen that can be reliably detected and that is less than the maximum expected amount of antibodies in the sample. An antigen:antibody complex is formed and becomes bound to a binding agent that does not bind free antigen. The free antigen is then detected as a measure of antibodies present in the sample.

Abstract: Apparatus for carrying out automatically in several successive steps an immunoassay of at least one biological substance in a plurality of biological samples, and the method and the reagents for the use of the said apparatus.

Abstract: An immunoassay element for quantitatively analyzing a ligand by determining the change in enzymatic activity. When the ligand is a low molecular weight antigen, competitive reactions between the ligand, enzyme-labelled antibody and conjugate of the antigen and high molecular weight compound are utilized. When the ligand is a macromolecular antigen, a reaction between the ligand and an enzyme-labelled antibody is utilized directly. The immunoassay element comprises a substrate layer containing a non-diffusible substrate which forms a diffusible material in the presence of the enzyme, and a reagent layer for detecting the thus formed diffusible material. The non-diffusible substrate is composed of a pulverized insoluble polysaccharide. The reagent layer may further contain a fragmenting enzyme for further fragmenting the non-diffusible material.

Abstract: The amount of an analyte in a sample derived from a living sample is measured by reacting the analyte with an excess of a substance having affinity for the analyte, followed by separation of complex by high pressure liquid chromatography and measurement using a linear calibration curve representing the peak area values associated with known concentrations of analyte.

Abstract: A method for the detection of nucleic acid-containing moieties is described which combines affinity capture of the moiety with detection and identification of the moiety's nucleic acid.

Abstract: A new homogeneous cytosolic binding protein (FKBP-14.6 immunophilin) having a molecular weight of about 14.6 kDa (calculated from its amino acid composition), reversibly binds the immunosuppressive drugs FK-506, rapamycin or chemically related compounds, but not cyclosporine. The FKBP-14.6 protein has a pI of 6.5-7.5, and the (partial) N-terminal amino acid sequence: NH.sub.2 -Lys-Leu-Pro-Tyr-Glu-Leu-Lys-X-Asn-Val-Lys-Ala-Phe-X-X-Lys-Val- (where X is undefined), and partial internal amino acid sequences -Val-Leu-Asp-Thr-Ala-Tyr-Glu-Tyr-Gly-Ala-Glu-Ala-Leu-Glu-, -Glu-Phe-Thr-Pro-Val-Phe-Gln-Ala-X-Phe- and -Ser-Leu-Val-Pro-Leu-Val-Gly-X-Lys- (where X is undefined). This N-terminal amino acid sequence exhibits no homology to FKBP-12 or membrane-associated FKBP-13. THe FKBP-14.6 is isolated from the cytosol of mammalian tissues, preferably calf thymus, and can be used in diagnostic and purification procedures involving FK-506 and rapamycin-type immunosuppressant drugs.

Abstract: The invention pertains to a single polypeptide chain binding molecule which has binding specificity and affinity substantially similar to the binding specificity and affinity of the light and heavy chain aggregate variable region of an antibody, to genetic sequences coding therefor, and to recombinant DNA methods of producing such molecule and uses for such molecule.

Abstract: The invention involves an immunological method of separating specifically-targeted cells or molecular structures from a mixed population under conditions which minimize damage to the cellular structure or the molecular integrity. The method is based upon the specific interaction of a label and an antibody directed against the label and the ability of a competitor to inhibit the interaction between the label and the antibody.

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: An assay device for detecting the presence of analytes in an unknown sample including a reaction system wherein storage reservoirs containing reagent are fluidly connected to a track containing the sample. An actuation mechanism forces the reagent from the reservoirs and into the track where it mixes the reagents together and then with the sample at a first flow rate. The mechanism then reduces the force on the reagent to allow a second flow rate less then the first flow rate to force the reagent and sample mixture through the track so that reaction can occur, whereby a determination as to whether the target analyte was present may be made.

Abstract: A biological sample such as feces, sputum, cervical tissue, pleural fluids, exudates, cytologic specimens, or the like, is tested for the presence or absence of: ova; parasites; microorganisms; inflammatory, neoplastic tissue cells; or other target materials which are indicative of infestation, disease or infection. The sample is mixed with a buffer fluid and placed in a transparent tube which contains a volume-constricting cylindrical insert for gravimetric separation of components of the sample. The mixture is centrifuged, and the annular space between the insert and tube bore is examined under magnification for the presence of the target materials.

Abstract: A vessel for conducting blood cell agglutination assays is disclosed. A barrier retains reactants in an upper chamber during incubation, then, in response to a force, permits reagents to enter a lower chamber containing a matrix for separating agglutination.

Abstract: The present invention provides methods and kits for determining the presence or amount of a substance by detection of a colloidal dye associated with agglutinated particles. The disclosure of the present invention shows that the use of a suspension of colloidal dye, which contains dye unattached to the particles to be agglutinated, enhances the amount of colloidal dye associated with the particles following agglutination. The methods and kits are disclosed in direct and indirect (e.g., competitive) formats. In one aspect, the present invention provides methods and kits utilizing a single colloidal dye. In another aspect, methods and kits are provided which include two colloidal dyes, wherein one colloidal dye functions as a background-enhancing dye.

Abstract: A method and a device for performing an assay in order to detect or determine the amount of an analyte in a test liquid, wherein bound and unbound reactants can be separated, comprising a capillary canal for liquid transport that is at least partly bordered by a semi-permeable layer, wherein during performance of an assay a movable solid phase material bearing a ligand capable of binding the analyte or binding a reactant for the analyte is within the capillary channel adjacent to the semi-permeable layer, said semi-permeable layer having pores that are sufficiently small to prevent the passage of the movable solid phase material and sufficiently large to permit passage of unbound reactants there through.