Abstract: A chromatographic assay device according to the present invention provides a unidirectional immunoassay for an analyte in a whole blood sample with improved sensitivity and freedom from interference.

Abstract: An assay device for the performance of immunochromatographic assays and other assays has two principal parts, a first opposable component and a second opposable component. The first opposable component can contain a sample preparation means and a second opposable component can contain a suitable chromatographic medium for detection of an analyte. Alternative embodiments of the invention can also exist. For example, the first opposable component can have a sample preparation means and a chromatographic medium that is not in communication with the sample preparation means and the second opposable component can contain a communicating means that, when the two components are brought into opposition, establishes a communication between the sample preparation means and the chromatographic medium. Assay devices according to the present invention can be used for both unidirectional and bidirectional assays.

Abstract: A chromatographic assay device for use with immunoassays allows rapid and convenient assays of analytes of biological interest, and permits extractions to be carried out in situ, avoiding the use of separate extraction vessels. The device has a wide dynamic range and avoids interference from particulates or colored components. In one form, the device comprises: (1) a first opposable component comprising a sample preparation means adapted to receive a sample to be assayed; and (2) a second opposable component comprising a chromatographic medium. The first and second opposable components can be brought into opposition so as to cause the sample preparation means to apply the sample to be tested to the chromatographic medium. Preferably, the analyte is detected with a visually detectable label. Other variations of the device vary the arrangement of components to provide optimal chromatography for a variety of analytes, as well as to permit bidirectional chromatography.

Abstract: A chromatographic assay device for use with immunoassays allows rapid and convenient assays of analytes of biological interest, and permits extractions to be carried out in situ, avoiding the use of separate extraction vessels. The device has a wide dynamic range and avoids interference from particulates or colored components. In one form, the device comprises: (1) a first opposable component comprising a sample preparation means adapted to receive a sample to be assayed; and (2) a second opposable component comprising a chromatographic medium. The first and second opposable components can be brought into opposition so as to cause the sample preparation means to apply the sample to be tested to the chromatographic medium. Preferably, the analyte is detected with a visually detectable label. Other variations of the device vary the arrangement of components to provide optimal chromatography for a variety of analytes, as well as to permit bi-directional chromatography.

Abstract: A chromatographic assay device for use with immunoassays allows rapid and convenient assays of analytes of biological interest, and permits extractions to be carried out in situ, avoiding the use of separate extraction vessels. The device has a wide dynamic range and avoids interference from particulates or colored components. In one form, the device comprises: (1) a first opposable component comprising a sample preparation zone adapted to receive a sample to be assayed; and (2) a second opposable component comprising a chromatographic medium. The first and second opposable components can be brought into opposition so as to cause the sample preparation zone to apply the sample to be tested to the chromatographic medium. Preferably, the analyte is detected with a visually detectable label.

Abstract: A chromatographic assay device for use with immunoassays allows rapid and convenient assays of analytes of biological interest, and permits extractions to be carried out in situ, avoiding the use of separate extraction vessels. The device has a wide dynamic range and avoids interference from particulates or colored components. In one form, the device comprises: (1) a first opposable component comprising a sample preparation zone adapted to receive a sample to be assayed; (2) a second opposable component comprising a chromatographic medium; and (3) a conductive barrier attached to the second opposable component. The first and second opposable components can be brought into opposition so as to cause the sample preparation zone to apply the sample to be tested to the chromatographic medium. Preferably, the analyte is detected with a visually detectable label. Other variations of the device vary the arrangement of components to provide optimal chromatography for a variety of analytes.

Abstract: A chromatographic assay device for use with immunoassays allows rapid and convenient assays of analytes of biological interest, and permits extractions to be carried out in situ, avoiding the use of separate extraction vessels. The device has a wide dynamic range and avoids interference from particulates or colored components. In one form, the device comprises: (1) a first opposable component comprising a sample preparation zone adapted to receive a sample to be assayed; (2) a second opposable component comprising a chromatographic medium; and (3) a conductive barrier attached to the second opposable component. The first and second opposable components can be brought into opposition so as to cause the sample preparation zone to apply the sample to be tested to the chromatographic medium. Preferably, the analyte is detected with a visually detectable label. Other variations of the device vary the arrangement of components to provide optimal chromatography for a variety of analytes.

Abstract: A chromatographic assay device for detection and/or determination of an analyte in a competitive immunoassay gives a semiquantitative or quantitative indication of analyte concentration in a single assay device while also giving a positive indication that flow has occurred properly through the device. In one form, the device comprises: (1) a first opposable component including a sample preparation zone and an absorber; and (2) a second opposable component including a first chromatographic medium with capture and detection zones, a second chromatographic medium with a comparison zone, and a comparison label. In another form, the second opposable component includes one chromatographic medium with capture, detection, and control zones. Test kits incorporating the devices and methods for their use are also disclosed.

Abstract: An assay device for detection and/or determination of an analyte in a test sample uses a barrier containing an aperture to control the application of reagents to the device for greater reproducibility of results. In its simplest form, the device comprises: (1) a chromatographic medium having a first end, a second end, and first and second surfaces, and having a specific binding partner for the analyte immobilized thereto in a detection zone; (2) at least one absorber in operable contact with at least one of the first and second ends; and (3) a substantially fluid-impermeable barrier adjacent to the first surface of the chromatographic medium, the barrier having at least one aperture therethrough for application of liquid to the chromatographic medium, the barrier at least partially blocking application of liquid to the chromatographic medium.

Abstract: The present invention provides chromatographic assay devices that can perform multiple assays simultaneously in the same test strip, as well as methods for their use. One of the assays can be an immunological assay to detect an antigen, such as human chorionic gonadotropin, while another assay can be a serological assay to detect an antibody, such as anti-rubella antibody. An assay device according to the present invention can comprise: (1) a first opposable component including at least one chromatographic medium having a specific binding partner to the first analyte and a specific binding partner to the second analyte immobilized thereto in separate, discrete, non-overlapping zones; and (2) a second opposable component including an absorber.

Abstract: The invention relates to a device and method for performing qualitative enzyme immunoassays. The device comprises at least one tube having antibody, antigen or hapten attached to an internal surface thereof. A first syringe is connectable to a first end of the tube or tubes and supplies a flow of test liquid therethrough. A second syringe having a two piston arrangement is connected to the tube so as to allow a first wash solution followed by an enzyme conjugate solution to be flowed therethrough. Finally a third syringe, also having a two piston configuration, is connected to the tube so as to allow a second wash solution followed by an enzyme substrate and metabolite indicator solution to be flowed therethrough.

Abstract: A device for use in detecting or determining the presence of antigenic or haptenic substances or antibodies in a sample comprises a plurality of tubular or capillary elements (1, 2, 3, 4, 5, 6), each having antibodies or antigenic or haptenic substances attached to an internal surface thereof, and means (11) for causing fluids to pass simultaneously or sequentially through the plurality of capillary elements. A method and test kit for detecting and determining the presence of antigenic or haptenic substances or antibodies in a sample by the enzyme-linked immunosorbent assay technique is characterized by use of urease as the enzyme in an antibody-enzyme or antigen-enzyme conjugate, with urea being used as the enzyme substrate and the presence of ammonia being detected or determined using di-bromo-o-cresolsulfonphthalein.

Abstract: A device for performing a plurality of immunochemical assays simultaneously comprises a waste reservoir about which are positioned at least two assay tubes connected in series by conduits formed in the base and top of the reservoir structure. A compound syringe is insertable into an opening formed through the top of the waste reservoir, the syringe being held in place by a receiving structure formed in the base of the reservoir and connected to the entrance end of the series of assay tubes. The various compartments of the compound syringe are emptied in sequence to cause the flow of sample and assay reagents to flow through the assay tubes. The device is structured to allow for the reflow of sample through the tubes if desired.

Abstract: The invention relates to a device and method for performing qualitative enzyme immunoassays. The device comprises at least one tube having antibody, antigen or hapten attached to an internal surface thereof. A first syringe is connectable to a first end of the tube or tubes and supplies a flow of test liquid therethrough. A second syringe having a two piston arrangement is connected to the tube so as to allow a first wash solution followed by an enzyme conjugate solution to be flowed therethrough. Finally a third syringe, also having a two piston configuration, is connected to the tube so as to allow a second wash solution followed by an enzyme substrate and metabolite indicator solution to be flowed therethrough.

Abstract: A method and test kit are disclosed for detecting the presence of antigens or antibodies in a sample by an enzme-linked immuno-sorbent assay using urease as the enzyme, urea as the enzyme substrate and di-bromo-o- cresolsulfonphthalein as the indicator.

Abstract: The invention provides a device for performing chemical or immunochemical assays quickly and on site. The device comprises a plastic molded body which may be miniaturized. The device is provided with a plurality of tubes for containing assay reagents, a small bore tube in which the assay is carried out, a sample tube, and conduit and valve means from the various tubes to the assay tube. The device is insertable into a programmable apparatus which controls the flows of the various reagents through the assay tube by means of plungers acting on pistons located in each reagent tube.