Abstract: A tube and float system for use in separation and axial expansion of the buffy coat is provided. The system includes a transparent, or semi-transparent, flexible sample tube and a rigid separator float having a specific gravity intermediate that of red blood cells and plasma. The sample tube has an elongated sidewall having a first cross-sectional inner diameter. The float consists of a main body portion and one or more support members protruding from the main body portion to engage and support the sidewall of the sample tube. The main body portion and the support members of the float have a cross-sectional diameter less than that of the first cross-sectional inner diameter of the tube when the sample tube is expanded, such as by centrifugation. The main body portion of the float together with an axially aligned portion of the sidewall define an annular volume therebetween.

Abstract: A test device (20) for detecting human blood includes a strip (22) having an introduction station (24), a test station (26), and a control station (28) disposed in spaced apart relationship. The test sample introduction station (24) has labeled antihuman Hb antibodies, the test station (26) has immobilized antihuman Hb antibodies, and the control station has immobilized polyclonal antibodies. A test sample (500) is deposited at the introduction station (24). If human hemoglobin is present in the test sample (500), a colored line will appear at the test station (26) and at the control station (28). If no human hemoglobin is present in the test sample (500), a colored line will only appear at the control station (28).

Abstract: An assay device and method are provided which allow the determination of the presence or absence of at least one analyte in a test sample, while providing specific identification of the test subject. The assay device includes a reaction medium having at least one reaction zone and at least one control zone, which is capable of providing a pattern suitable for identifying the test subject. The pattern suitable for identifying the test subject is preferably a fingerprint. In a preferred embodiment of the invention, the reaction zone and the control zone include at least one member of a ligand/receptor pair.

Abstract: This invention provides a novel Cryptosporidium parvum protein disulfide isomerase polypeptide, and nucleic acids that encode this polypeptide. The invention also provides methods, reagents, and kits that are useful for diagnosing infection by Cryptosporidium parvum. The methods are based on the discovery of binding agents, including recombinant polyclonal antibodies, that bind to the protein disulfide isomerase polypeptide of C. parvum.

Abstract: A binding assay device includes a porous membrane comprising a material enabling capillary movement of a liquid sample from a first area on the membrane on a second area on the membrane. A detection site is disposed on the membrane between the first and second areas in a non-absorbent medium disposed on the membrane between the detection site and the membrane first area is attached by an adhesion with a dry reagent disposed between the medium and the membrane in order to enable mobilization of the reagent by passage of a liquid sample therepast.

Abstract: An improved multi-layered diagnostic sanitary test strip for receiving a heterogenous fluid, such as whole blood, to test for presence and/or amount of a suspected analyte in the fluid by facilitating a color change in the strip corresponding to the amount of the analyte in the fluid, wherein the test strip includes fluid volume control dams to prevent spillage of the fluid from the strip and a chemical reagent solution that facilitates end-point testing.

Abstract: The invention provides an improved test cell for detecting the presence of an analyte in a liquid sample. The device has an elongate casing defining a liquid sample inlet, a reservoir volume, a test volume, and a window through the casing at the test volume. Disposed within the cell is a sample absorbent, a novel biphasic substrate and a reservoir, together capable of transporting an aqueous solution within the casing along a flow path extending from the sample inlet through the test volume and into the reservoir volume. The invention further comprises a method for detecting the presence of an analyte in a liquid sample using the device and a biphasic chromatographic material for carrying out the method.

Abstract: An assay device for determining an analyte in an aqueous sample comprises: (i) an elongate flow matrix (6) allowing lateral transport of fluid therethrough by capillary action, wherein the matrix comprises a liquid application zone (3) and downstream thereof, a detection zone (8) having an immobilized capture agent capable of directly or indirectly binding to said analyte, (ii) a wicking member (13) placed at the downstream end of the flow matrix and having an upstream end and a downstream end, and (iii) a time indicator (14) placed downstream of the detection zone (8) for indicating when liquid applied to the liquid application zone has reached the time indicator. The time indicator comprises an indicator substance or substance combination which is capable of exhibiting a visible color change when hydrated by the aqueous sample.

Abstract: This invention provides a novel device and method for preparing cytology slides. The device comprises a book-like form including an absorbent material and filter attached to the inside surface of a front cover and a cytology slide removeably attached to an inside surface of a back cover. A sample is removed from the body of a patient, placed in a liquid-based solution, and then on the filter. When the book-like form is closed, the sample is effectively transferred to the slide. The device can be modified so that a plurality of slides are prepared at the same time.

Abstract: A device for collecting oral liquids includes a lateral flow chromatography strip having a collection pad for insertion into the mouth. The collection pad is separated from the remainder of the chromatography strip by a liquid impermeable removable barrier which prevents liquid in the collection pad from entering the chromatography strip. Once adequate oral liquid has been collected (as indicated by a sample sufficiency indicator), the device is withdrawn from the mouth and the barrier is removed to allow oral liquids to flow through the strip. The liquids interact with binding partners in the strip to provide test results, such as an indication that an analyte of interest is present in the liquid. The strip may be contained in a housing with an access opening through which the removable barrier may be manipulated, and windows through which test results may be viewed. This device avoids reflux of reagents from the strip into the mouth of a test subject during use.

Abstract: The invention concerns a method for the detection of an analyte in a sample using analyte-specific conjugates which have at least one heterologous group for an analyte-independent binding to a control zone. The present invention additionally provides new conjugates and reagent kits.

Abstract: An improved multi-layered diagnostic sanitary test strip for receiving a heterogenous fluid, such as whole blood, to test for presence and/or amount of a suspected analyte in the fluid by facilitating a color change in the strip corresponding to the amount of the analyte in the fluid, wherein the test strip includes fluid volume control dams to prevent spillage of the fluid from the strip and a chemical reagent solution that facilitates end-point testing.

Abstract: A method to determine the presence or absence of Streptococcus Group A antigen in a sample, comprising the following steps: extracting the antigen from the sample in an assay chamber with two or less extraction reagents, wherein the two reagents may be added to the assay chamber in no particular sequence; introducing a lateral flow immunochromatographic assay device into the extraction reagents containing the extracted antigen without further addition of reagents or manipulation of the sample; forming an antigen-indicator labeling reagent complex; and determining the presence or absence of the antigen in the sample by the presence or absence of a signal formed by the binding of the antigen-indicator labeling reagent complex to an indicator capture reagent specific for said antigen-indicator labeling reagent complex.

Abstract: Disclosed is a testing device and methods for the identification of an analyte of interest in a sample. In a preferred embodiment, the testing device includes a front panel having at least one sample application aperture; a rear panel having at least one solvent application aperture; a sample collection matrix disposed between the rear panel and the front panel, the sample collection matrix being in communication with the sample and solvent application apertures of the front and rear panels; and at least one insertable test strip containing a reagent enabling detection of the analyte of interest.

Abstract: An assay method and kit for detecting the presence of a predesignated, target IgG antibody in a sample selected from one or more patient bodily fluids. The method comprises the following steps: (a) contacting the sample of one or more patient bodily fluids with a membrane-bound recombinant protective antigen to bind to the target IgG antibody in the sample; (b) previously, simultaneously or subsequently to step (a), binding the protective antigen (PA) with a conjugated label producing a detectable signal; and (c) detecting the signal whereby the presence of the target IgG antibody is determined in the sample by the intensity of the signal. The method can further comprise the step of evaluating immunization status of the patient from whom the sample came by comparing the signal or lack thereof with immunizations previously received by the patient. In a preferred embodiment, the recombinant protective antigen (PA) specifically binds to anthrax protective antigen-specific IgG antibodies.

Abstract: This invention provides solid phase specific binding lateral flow assay methods, devices and kits for quantitating high and low molecular weight analytes. The methods and devices of the invention employ labelled reagents which are either analyte analogs or complementary specific binding pair members for the analyte and a novel arrangement of capture zones comprising immobilized specific binding substances for either the analyte or the labelled reagent to effect bound from unbound labelled reagent as a function of analyte concentration. The capture zones are disposed on a non-bibulous matrix defining a flow path from a sample receiving zone to the capture zone. The devices of this invention also include multilane flow paths and multiple capture zones to quantitate analyte.

Abstract: A non-instrumental assay for the diagnosis of celiac disease based on the general immunochromatographic assay principles. The assay is rapid and simple and allows the reliable detection of anti transglutaminase antibodies, of both IgA and IgG isotype, in samples of human serum, plasma or blood, using as tracer the antigen transglutaminase conjugated to a colored substance, like colloidal gold or colored latex particles. The conjugated antigen is deposited onto an inert fibrous support, from where it can be released by a liquid sample. The antibodies in the sample react with the conjugated antigen developing an immunocomplex that migrates through a carrier membrane, like nitrocellulose or nylon with a pore size that allows a laminar flow of the reagents, until it reacts with the same antigen transglutaminase immobilized onto a reactive zone of the membrane. As a consequence of this reaction the immunocomplex will be trapped in the reaction site and a colored signal will be seen.

Abstract: The present invention provides a method and a device that utilizes capillarity-mediated, chromatographic transport, for the qualitative or semi-quantitative analysis of selected analytes in liquid samples. The device utilizes an applicator/collection device for collecting and administering the sample to the flow path such that reagent(s) flow through the applicator/collection device, washing the sample into the reaction pathway. The device further utilizes an air gap between the initial location of the reagent and the reaction pathway to funnel the reagent efficiently through the sample so as to collect all or substantially all of the sample and make it available for the reaction(s).

Abstract: This invention provides a novel device and method for preparing cytology slides. The device comprises a book-like form including an absorbent material and filter attached to the inside surface of a front cover and a cytology slide removeably attached to an inside surface of a back cover. A sample is removed from the body of a patient, placed in a liquid-based solution, and then on the filter. When the book-like form is closed, the sample is effectively transferred to the slide.

Abstract: Test strips for determining the concentration of at least one analyte, e.g., glucose, in a physiological sample and methods for their manufacture and use and are provided. The subject test strips include a transfer element for facilitating the transfer of sample to a reaction area of the test strip. In certain embodiments, the transfer element, typically porous, has a first area and a second area, and in certain embodiments the two areas have different thicknesses. In other embodiments, the transfer element is non-porous and is configured to transfer sample by wicking it between the transfer element and the reaction area of the test strip. In the subject methods, the transport element facilitates transfers of a sample to a reaction area of the test strip. The subject test strips and methods find use in a variety of different applications, particularly in the determination of glucose concentrations.

Abstract: The present invention relates to articles of manufacture inclusive of or in combination with a biological assay material, formed from a material capable of detecting and identifying the presence of one or more particular toxic substances, wherein said toxic substances may comprise a multiplicity of biological materials.

Abstract: Disclosed is a device useful for performing an assay comprising a substrate having interconnecting channels that open out onto a surface for sample application, the channels being provided in at least one cross-sectional area with a first binding substance capable of binding a particular analyte, the substrate being an electrochemically manufactured metal oxide membrane and containing the first binding substance within the through-going channels. Similar devices are also useful for chemical synthesis. Assay and chemical synthesis methods are also disclosed, as are kits for performing the assays or chemical syntheses.

Abstract: The invention relates to an assay for testing oxidative stress of a subject by measurement of oxidants in biological fluids such as urine, plasma, bioreactor medium and respiratory aspirants. There is provided a method of determining oxidative stress in a mammalian subject. The method comprises: obtaining a sample of a biological fluid from the subject; mixing the biological fluid with a ferrous reaction reagent; incubating the biological fluid and the reaction reagent; and detecting a colored reaction product. There is further provided a ferrous reaction reagent suitable for use in assaying oxidative stress, said reaction reagent comprising 2-deoxyglucose, TBA, EDTA, and ferrous sulfate, and being substantially free of ascorbic acid.

Abstract: The present invention is directed to methods for analyzing one or more fluid samples for the presence, amount or identity of one or more analytes optionally present in said samples, which uses a device having one or more round wells with a fixed diameter, the wells exposing a substrate of a specific thickness, whereby the substrate has oriented through going channels, in the area of the substrate exposed in the well is provided with at least one binding substance specific for a least one of said analytes. Using the device the sample fluid is forced to pass through the channels in the substrate from the upper side of the substrate to the lower side of the substrate and back at least one time, under conditions that are favorable to a reaction between any analyte present in the sample and the binding substances.

Abstract: Assay devices, kits, and methods for detection of one or more analytes in a sample are provided. The assay device features the controlled release of reagents and hence is particularly suitable for binding assays such as immunoassays. The assay device achieves greater sensitivity than conventional rapid test assays, leading to stronger and/or more stable visual signals than those produced by conventional devices, easier interpretation of results, and reduced occurrence of indeterminate results. The device can be used for detecting analyte in a variety of biological samples without the need for conventional sample filtration techniques, and thus is suitable for use by untrained personnel without specialized equipment. In addition, the device can be used to simultaneously analyze a number of analytes using a single sample.

Abstract: Disclosed is an improvement to a dry assay device for determining the concentration of a first analyte in a sample of body fluid and a second analyte in the same sample of body fluid. The device involves the use of a strip of an absorbent material through which the sample of body fluid flows and wherein the first analyte is determined colorimetrically in a first region of the strip and the second analyte is determined by an immunoassay which takes place in a second region of the strip located downstream from the first region. The improvement involves placing the strip in a hollow casing having a top and a bottom and which is so constructed that when the top and bottom of the casing are mated there is formed a U shaped, body fluid impervious barrier around the first region of the strip to prevent the sample of body fluid from flowing in any direction other than in the direction of the second region of the strip.

Abstract: Disclosed is an improvement in the analysis for an analyte in a urine test sample in which the urine is contacted with a labeled antibody specific to the analyte and the concentration of the analyte is determined by measuring the response from the label. The improvement involves maintaining the concentration of urea in the test sample above the threshold value which value is the concentration of urea at which increases in the urea concentration do not affect the accuracy of the assay such as by interfering with the binding between the analyte and the labeled antibody.

Abstract: This invention discloses a method and composition for detecting the presence of class specific antibodies reactive with analytes such as bacteria, allergens, autoimmune antigens, viral proteins, and carbohydrates by lateral flow techniques. In one embodiment of the invention, a test sample obtained from bodily fluids reacts with a gold labeled antigen. The resulting complex travels across the membrane, and along the lateral flow strip. Red colored lines formed in specific locations along the test strip indicate the presence of class specific antibodies in the test specimen. In another embodiment of the invention, the lateral flow assay serves as an immunochromatographic screening test for the detection of allergen-specific IgE antibodies in human serum. Test sample reacts with gold labeled anti-IgE antibody. The resulting complex travels across the membrane where immobilized allergens capture the allergen specific IgE complex.

Abstract: A lateral flow immunoassay device includes a membrane strip for enabling capillary migration of a sample therealong with a labeled reagent disposed on the membrane. The label reagent is formulated for suspension in the sample migrating therepast. A captive reagent is immobilized on the strip on a path of sample migration and the captive reagent is formulated to bind to the labeled reagent to form a visible colored site on the strip. An element is provided for changing the strip to a color which enhances visual perception of the colored site.

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, 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 me

Abstract: A test device and a kit for conducting an assay for the determination of an analyte in a sample comprises (i) a housing (1,2), and within said housing, (ii) a flow matrix (6) allowing liquid to be transported by capillary action and having at least one zone with immobilized capturing agent capable of directly or indirectly binding to the analyte, (iii) a liquid container (13) for sample liquid, and (iv) at least one liquid container for liquid other than sample liquid. The device further comprises (v) separation means (5) between the flow matrix (6) and the liquid containers (13), wherein said separation means (5) are mounted in movable relationship with the liquid containers to in a first position prevent liquid contact of the flow matrix (6) with the liquid containers (13), and in a second position permit liquid receiving contact of the flow matrix (6) with the liquid containers (13).

Abstract: A method of making strip for testing for the presence of an analyte generally comprises providing a support member which includes a spreading layer and a reagent layer, and a capillary in communication with the support layer and spreading layer for transporting a sample of body fluid thereto.

Abstract: The invention provides an improved test cell for detecting the presence of an analyte in a liquid sample. The device has an elongate casing defining a liquid sample inlet, a reservoir volume, a test volume, and a window through the casing at the test volume. Disposed within the cell is a sample absorbent, a novel biphasic substrate and a reservoir, together capable of transporting an aqueous solution within the casing along a flow path extending from the sample inlet through the test volume and into the reservoir volume. The invention further comprises a method for detecting the presence of an analyte in a liquid sample using the device and a biphasic chromatographic material for carrying out the method.

Abstract: An immunoassay device and assay to detect an antigen, such as PSA, in a biological sample. The device comprises a solid support having multiple reaction zones containing capture antibodies directed to the antigen. Exposure of a test sample to a mixture of incubation antibodies with known and different concentrations prior to exposure to the capture antibodies in the reaction zones facilitates determination of a range of concentrations of the antigen.

Abstract: It has been found that casein and salts of casein are useful as replacements for, or in addition to, BSA as materials for coating solid phases, particularly magnetic particles, used for immunoassays and other binding assays for separation of the desired analyte. By using casein, immunoassays having improved stability and few discordant samples have been developed. Casein used at a concentration of 0.05-4.0 grams per gram of paramagnetic particle (optimally approximately 0.78-1.2 grams of casein per gram of magnetic particle) has been found to confer this benefit. In addition, a process for coating solid phases has been invented, said process comprising the mixing of casein with magnetic particles at 30-60° C. for 5-180 hours, said process resulting in casein-coated paramagnetic particles which either (1) already have combined therewith active ingredients needed in the binding assay or (2) are capable of reacting with active ingredients needed in the binding assay.

Abstract: A catcher, having an immunological epitope, is fixed to a detection zone of a spreading layer. A marker, capable of easy detection, has an inmmunological epitope. The marker and bispecific antibodies are soluble so that they can move on the spreading layer. The bispecific antibodies include a first bispecific antibody, having specificity for the detectable material in the fluid sample and the marker, and a second bispecific antibody, having specificity for the detectable material in the fluid sample and the catcher. Pore sizes and particle diameters are set so that the reaction product in which the marking elements and the particles are bonded are caught at a catching section. The concentration of the marking elements and the particles are increased to improve detection sensitivity. The result is an inexpensive and simple detection apparatus being highly-sensitive for the immunological detection of a detectable material, without wasting valuable antibodies.

Abstract: The invention relates to a method for determining an analyte by means of binding reactions, which method comprises: i) applying the sample to an application zone for sample (ASZ) on a flow matrix in which transport of components present in the sample can take place (transport flow), the flow matrix further exhibiting: a) optionally an application zone (AR*Z) for a binding reactant (Reactant*=R*) which is analytically detectable; b) a detection zone (DZ), which is located downstream of ASZ and exhibits an additional binding reactant (Capturer) firmly anchored to the matrix, and in which a complex (signal complex) containing the Capturer and the analyte and/or Reactant* is formed during the reaction, and ii) detecting the signal complex in the detection zone, the measured signal being used for determining the analyte.

Abstract: An immunochemical assay device comprising a base member, an array disposed on the base member, and at least one assay indicia zone. The array comprises (i) a reservoir pad to receive sample liquid, (ii) a wicking membrane, and (iii) at least one filter zone interposed between the wicking membrane and the reservoir pad. The filter zone being operable to permit passage of any specific immunocomplex to the wicking membrane while impeding passage of larger components.

Abstract: A kit containing the reagents necessary for the qualitative or quantitative demonstration of epidermal growth factor receptor (EGFR) in formalin-fixed, paraffin-embedded tissue sections. A immunohistochemical staining procedure is employed which utilizes a primary monoclonal mouse antibody that selectively binds to EGFR. The primary antibodies bound to tissue antigens are detected using a peroxidase labeled polymer that is conjugated with secondary anti-mouse immunoglobulin antibodies. The enzymatic conversion of the subsequently applied chromogen results in formation of a visible reaction product at the site of the EGFR antigen. Following development of the chromogen, specimens may then be counterstained and coverslipped. Results are interpreted using a light microscope or other optical imaging device. The detection system is adapted for both manual and automated staining.

Abstract: A method for determining and diagnosing inflammatory enteric disease using an immunochromatographic test device having a multiplicity of test zones. The method tests for the presence of at least one enteric pathogen and at least one of certain inflammatory enteric disease markers. The enteric pathogens tested for can be any number of enteric pathogens such as the pathogens E. coli O157, Campylobacter, Salmonella, Listeria, Shigella, and Yersinia. The inflammatory enteric disease markers tested for are fecal lactoferrin, a bacteria marker, a virus marker, and a protozoa marker. Positive results for any one of the pathogens indicates that pathogen as the cause of the inflammatory enteric disease. Positive results for fecal lactoferrin indicate an inflammatory condition of the intestines. Positive results for the bacteria, virus, protozoa markers indicate respectively a bacterial, viral, or protozoan cause of infection as the cause of the disease.

Abstract: The present invention involves a method and an immuno-analytical device for the rapid and simultaneous detection of multiple micro-organisms in the biological fluids from milk-producing animals suffering from mastitis. This method is based on a lateral flow immuno-assay technique performed to detect antigens specific for multiple infectious agents which are known to cause and/or be encountered in cases of mastitis. Mastitis is an inflammatory condition affecting the udders of milk-producing animals as a result of microbial infections.

Abstract: The invention relates to an immunoassay apparatus, comprising a dry, porous substrate having at least two sections (1, 2), communicating with one another in the moist state by capillary action, wherein the first section (1) has a marked detection reagent for the substance to be detected and the second section (2) has an immobilized binder reagent for the substance to be detected, and wherein the reaction product comprising the substance to be detected and the marked detection reagent migrates by capillary action from the first section into the second section in the moist state, and is characterized in that the marked detection reagent is a dye-carrying reagent for nicotine or cotinine.

Abstract: The present invention relates to bioassay materials useful for the detection of toxic substances and, more particularly, to packaging materials for food and other products, along with methods for their manufacture and use. The invention provides a unique composite material capable of detecting and identifying multiple biological materials within a single package. The biological material identification system is designed for incorporation into existing types of flexible packaging material such as polyvinylchloride or polyolefin films, and its introduction into the existing packaging infrastructure will require little or no change to present systems or procedures.

Abstract: A test device (20) for detecting semen includes a strip (22) having an introduction station (24), a test station (26), and a control station (28) disposed in spaced apart relationship. The introduction station (24) has labeled p30 antibodies, the test station (26) has immobilized p30 antibodies, and the control station has immobilized polyclonal antibodies. A test sample (500) is deposited in the introduction station (24). If semen is present in the test sample (500), a colored line will appear at the test station (26) and at the control station (28). If no semen is present in the test sample (500), a colored line will only appear at the control station (28).

Abstract: One embodiment of the present invention improves the visual use of urine test strips and reagent pads by providing a single color from a reference color spectrum directly on the colorimetric strip and adjacent to the reagent area to allow easy comparison. After application of a fluid to be tested to a reagent area on the colorimetric strip, a technician is able to easily compare the color in the reagent area to the reference color area(s) to determine the presence or absence of, for example, glucose, in the fluid. Placing at least one reference color immediately next to the reagent area markedly improves technician's accuracy in comparing and analyzing the reagent area against the reference color(s). The present invention allows a technician to easily and quickly compare a reagent area color to more than one reference area to determine the actual numerical value of, for example, the pH in the tested fluid.

Abstract: A method of determining the concentration of IgG antibodies in the biological fluids of mammals. The assay may be performed in a lateral flow cassette or dipstick format where dehydrated immobilized reagents are spaced along a membrane. A sample of a mammalian biological fluid is exposed first to an IgG complexing agent to yield a conjugate. The conjugate then moves along the membrane and is exposed to a standard mammalian IgG applied to the membrane at a test position. Binding of the IgG is indicated by a color change at the test position on the membrane. A control reagent of dehydrated anti-IgG complexing agent may be applied to the membrane at the control position spaced downstream from the test position. Interaction of the IgG complexing agent with the anti-IgG complexing agent forms a visible line at the control position on the membrane.

Abstract: The present invention relates to an immunoassay device featuring a semi-quantitative, multi-level method for determining the presence and an amount of an analyte. The immunoassay involves a device comprising a layer with a porous medium deposited thereon. The device has several binding zones in which each zone comprises a defined amount of a binding reagent to bind and immobilize the analyte. The present invention also features an inscribed capillary channel having fluid barriers that allow control of a rate of migration of fluid along the porous medium. The device typically provides at least some of the binding zones within the capillary channels such that a solvent quickly traverses through the capillary channels and provides a semi-quantitative result. Preferably, any binding of an analyte is accompanied by a visual change in the binding zone such that one can easily detect visually an amount of analyte present in the sample.

Abstract: Disclosed is a device and method of use for detecting polyvalent analytes such as antibody to the AIDS virus, utilizing an inverse sandwich method. The test device comprises a first substance having an epitope, bound to a label and capable of moving within the test device. The test device further comprises a second substance immobilized to the test device and spatially separated from the first substance. The second substance has an epitope substantially similar to the epitope of the first substance. Upon application to the test device, the polyvalent analyte binds to the first substance and moves within the test device to the location of the second substance with both polyvalent analyte and first substance are immobilized at location of the second substance. Polyvalent analyte is detected by the presence of the label at the location of the second substance. Also disclosed is a control substance for use with the device that can be used to determine completion of the test and viability of the device.

Abstract: A solid diagnostic device for the quantitative determination of substances of biological affinity in biological fluids is described. A process is also described in which the biological fluid is brought into contact with a specific functional sector of the device, the fluid migrates through several functional sectors situated beside one another and containing suitable reagent components, and one or more substances of biological affinity are detected in such functional sectors which contain, for each substance to be detected, at least one combination partner of biological affinity, attached to a solid phase.

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.