Abstract: An immunity testing device formed of a thin sheet of material folded to three portions, and the two end portions; named “front cover”0 and “back cover”; fold back to different sides of the center part; named base seat; to provide protection on both sides of the base seat. Two absorbent sheets bridged with a test paper are fixed on the side of base seat that's facing the front cover. A hole is present at the position of the first absorbent sheet on base seat for specimen application. The front cover is disposed with observation cover plates at the position corresponding to the test paper and/or water-absorbing sheets for observation of test result as well as for preventing pollution before, and after use. The test paper is pre-embedded with antibodies/antigens to capture the corresponding antigens/antibodies in the test specimen as in Immunity method. The used testing device can be burned down to ensure environmental protection.

Abstract: A displacement-type flow immunoassay is performed using a microcapillary passage. The inner wall of the microcapillary passage has immobilized thereon antibodies to the antigen of interest. Labeled antigen is immunologically bound to the immobilized antibodies. Sample antigen passing through the column displaces the labeled antigen. Downstream, the displaced labeled antigen is detected. The microcapillary format of the present invention enhances the sensitivity of the immunoassay over the sensitivity of displacement-type flow immunoassays performed in a column at similar flow rates.

Abstract: An analytical element can be used to sensitively and rapidly detect a wide variety of specific binding ligands in either a competitive or sandwich assay format. The assays are carried out using a vanadium bromoperoxidase-labeled immunoreactant and a chemiluminescent signal-providing wash composition which comprises a 2,3-dihydro-1,4-phthalazinedione derivative; a halogen, pseudohalogen, halogen-providing source or pseudohalogen-providing source; and a peroxide or a peroxide-generating reagent composition.

Abstract: An electronic device for performing active biological operations includes a support substrate, a second substrate, a source of illumination, and an edge illumination layer. The support substrate includes first and second surfaces and a via between the first and second surfaces to permit fluid flow through the substrate. The second substrate includes a first surface that is adapted to be disposed in facing arrangement with the second surface of the first substrate. The second substrate includes an array of microlocations wherein the array is adapted to receive the fluid. A sealant is disposed between the second face of the support substrate and the first face of the second substrate. The device includes a source of illumination and an edge illumination layer having an input adapted to receive the illumination from the source, and an output adapted to direct the illumination to the array. The edge illumination layer is disposed adjacent to and between the support substrate and the second substrate.

Abstract: A method and apparatus for fabricating replicate arrays of nucleic acid molecules include the preparation of the molecules and the application the molecules onto a substrate in an ordered array. The apparatus comprises a synthesis unit and a plurality of outlets. The synthesis unit comprises a plurality of synthesis chambers that are spatially arranged relative to each other to provide an array suitable for conducting parallel nucleic acid syntheses. The chambers are suitable for containing discrete compositions of nucleic acid molecules. Each outlet of the plurality of outlets communicates with a single synthesis chamber. The plurality of outlets are configured such that nucleic acid molecules can be removed from the chambers through the outlet and deposited onto the substrate in an ordered array that corresponds to the spatial arrangement of the synthesis chambers.

Abstract: One-step enzyme immunoassays in which enzyme-antibody conjugate or label and enzyme substrate are separated until separation of bound and free enzyme conjugate or label is complete. This separation is accomplished by using variable flow paths, immobilization of substrate at the test line, placement of substrate in a sac or association with a particle label, enzyme product chemical capture, delay zone dissolution and protected enzyme substrates.

Abstract: Microporous solid phase materials that are suitable for lateral flow and other assays for detecting the presence of analytes in test samples, that are stable under variations in humidity and, even after storage for extended periods of time, can form stable covalent bonds with molecules containing a free primary or secondary amine group or sulfhydryl group are described. The invention further concerns chemically derivatized solid phase materials, and conjugates comprising such materials. Examples of lateral flow devices for the quantitative or semi-quantitative determination of an analyte in a biological sample are described.

Abstract: The invention includes assay cassettes that can be employed during rapid flow-through binding assays. The assay cassettes can be disposable units suitable for one-time use and readily assembled to include a filter membrane carried between an upper plate and a lower plate. A pattern of channels can extend through the top plate to allow a fluid sample to be applied through the top plate and onto the filter. The bottom plate can include a plurality of channels that are aligned with the channel of the top plate and which will allow a negative pressure to be applied to the underside of the filter membrane to draw the sample through the filter. In one embodiment, the cassette includes a frangible section that allows the cassette to be divided into a first and second component.

Abstract: Devices for use in heterogeneous ligand-receptor assays, having a porous member in contact with a nonabsorbent textured surface, where the surface texturing is such that a capillary network is formed when in fluid communication with the porous member. More particularly, these devices comprise: (a) a porous member having (i) at least one binding agent capable of immobilizing at least one target ligand on the porous member from a fluid sample in at least one zone and (ii) a means for detecting the presence or amount of said target ligand as a result of the assay process; and (b) a nonabsorbent member in fluid communication with the porous member, the nonabsorbent member forming at least one capillary with the porous member so that when sample, alone or in combination with other fluids, is added to the porous member, fluid is drawn through the porous member.

Abstract: Methods of manufacture and devices for performing active biological operations utilize laminated structures. In the preferred embodiment, a first planar sample support includes at least one sample through hole, a planar electrode is disposed adjacent the first planar sample support, and includes an electrode through region, a second planar support includes a vent through hole, the planar electrode being in a laminated relationship between the first planar sample support and the second planar support, further characterized in that the sample through hole, electrode through hole and vent through hole are in overlapping arrangement. Preferably, some or all of the through holes, through regions and vent through holes are aligned. In one embodiment, the lateral dimension of the vent through hole is larger than the lateral dimension of the electrode through hole. In an alternative embodiment, the lateral dimension of the sample through hole is larger than the lateral dimension of the vent through hole.

Abstract: The present invention involves an optical assay device and method of use for the detection of an analyte of interest in a sample that conveniently allows control of the flow characteristics of the sample through the device without significant user intervention. The optical assay device includes a base having an absorbent material, and a member having an optically active test stack that is rotatably coupled to the base for rotation between a lowered position and a raised position. In the lowered position, the optically active test stack contacts the absorbent material for drawing the sample through the surface. In the raised position, the optically active test stack does not contact the absorbent material.

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. The improved test strip comprises (a) an upper support strip having a fluid receiving port and (b) a lower support strip having a color change viewing port and securely sandwiched therebetween (c) a spreading mesh screen for uniformly distributing the fluid, (d) a chemically treated separating layer for removing an undesirable element, e.g.

Abstract: The invention relates to surfaces coated with streptavidin and avidin for use in immunoassays, wherein the surfaces comprise a layer of streptavidin and avidin which are bonded on a surface of a solid supporting material through a biotinylated adhering agent.

Abstract: A strip for testing for the presence of an analyte generally comprises a support member which contains a spreading layer and a reagent layer, and a capillary tube in communication with the support layer and spreading layer for transporting a sample of body fluid thereto. A method of testing a fluid for the presence or concentration of an analyte is also provided which generally includes providing a test strip with a support member, a spreading layer, and a reagent layer on the spreading layer. A capillary tube is provided on the support member whereby a fluid containing an analyte to be tested is introduced into the tube and flows through the tube to the spreading layer and contacts the reagent layer.

Abstract: Lateral flow device and method are provided for performing semi-quantitative visual or instrument-based detection in a test sample of a large molecule analyte that contains two binding domains, &agr; and &bgr;. The device contains two reagents, a contrast reagent and an indicator reagent, and an analyte test zone (ATZ) that contains a fixed number of immobilized &agr;-domain-specific binding sites. The contrast and indicator reagents each contain signal generators such that the two reagents contrast each other in different regions of a visual, spectrophotometric, calorimetric or fluorometric spectrum. The contrast reagent is prebound to an &agr;-region-fragment of the analyte of interest and, therefore, does not react with the analyte of interest in the test sample. The indicator reagent is attached to a binding ligand specific for the &bgr;-domain of the analyte of interest.

Abstract: A device that provides for both the collection of saliva and detection of at least one analyte therein, e.g., a drug, is provided. This device provides for rapid analysis of saliva samples, while also providing a convenient assay method that does not require the addition of extraneous reagents, or other materials. Thereby, this device can be used by non-laboratory personnel without risk of user introduced errors.

Abstract: Substrates are patterned with antibodies attached thereto at discrete locations from which absorption resistant coating is removed by selectively controlled mechanical scribing contact to avoid chemical removal so as to decrease fabrication costs and increase fabrication speed.

Abstract: The subject invention relates to a rapid, field-portable, modular, versatile and highly reliable assay device for substances, particularly drugs of abuse, which provides a positive signal in the presence of a specific substance for which the device has been specifically adapted to test. The subject invention also concerns methods for making and using the assay device. The device is easily and reliably manufactured by laminating a series of manufactured layers to each other to form an upper card assembly and a lower card assembly. The upper card assembly is bonded to the upper side of a layer which has an immobilized reagent specific for a test substance bound thereto, and the lower card assembly is bonded to the lower side of the layer having the immobilized reagent. The device can be manufactured and distributed in a unitary, ready-to-use form.

Abstract: The invention relates to multiplex ligase chain reaction (LCR). Two or more putative target sequences are selected. For each one, a set of four probes is used simultaneously to amplify the putative sequence if it is present in the sample. Preferably, all the amplicons are labeled with a common label/hapten and, for each different target, with a unique label/hapten. The invention also relates to an immunochromatographic strip device and method employing a diagonal array of capture spots.

Abstract: A reagent is suitable for measuring the concentration of an analyte in a hemoglobin-containing biological fluid, such as whole blood. The reagent comprises dehydrogenase enzyme that has specificity for the analyte, NAD, an NAD derivative, pyrrolo-quinoline quinone (PQQ), or a PQQ derivative, a tetrazolium dye precursor, a diaphorase enzyme or an analog thereof, and a nitrite salt. The reagent causes dye formation that is a measure of the analyte concentration. The nitrite salt suppresses interfering dye formation caused non-enzymatically by the hemoglobin. Preferably, the reagent is used in a dry strip for measuring ketone bodies, such as beta-hydroxybutyrate.

Abstract: A device and method allow for detecting the presence of microorganisms in clinical and non-clinical specimens. The device, a sensor, provides an environment to culture microbial organism colonies from a fluid sample, and a means to facilitate microbial detection and quantification, either manually or with an instrument. The sensor has a microorganism immobilization matrix layer and a sensor layer. Detected microbial colonies are immediately available for further testing. The sensor provides an area for accepting a fluid sample, a mechanism to immobilize the fluid sample on an interior surface of the plate, nutrients to facilitate growth of microorganisms in the sample, and a sensor for allowing the detection and/or enumeration of microorganism colonies within the sample.

Abstract: A device for the separation of the liquid portion of blood from the cellular components of blood comprises: (1) a pad of porous material permeable to the liquid portion of blood but capable of trapping the cellular components of blood; (2) a substrate supporting the pad; and (3) means, attached to the pad, for facilitating the flow of the liquid portion of the blood: (i) through interstices around the trapped cellular components of the blood and (ii) from the pad of porous material. The separation of the liquid portion of blood from the cellular components of the blood occurs by flow through the pad of porous material without significant hemolysis. The device can be incorporated into a device for the performance of specific binding assays such as immunoassays. The pad of porous material can contain an agglutinating agent such as a lectin or an anti-blood cell antibody, or a carbohydrate such as mannitol.

Abstract: A diagnostic test strip for determining the presence of a specified analyte in a fluid sample is described. The test strip has a test membrane sandwiched between two layers of a plastic sheath. The upper layer of the sheath has a sample well into which a liquid sample is placed. The test membrane has a sample receiving zone typically containing a buffer and a fatty acid sarcosinate. Adjacent to the sample receiving zone is a reagent zone containing reagent chemicals including gold colloid particles coated with antibodies to the specified analyte. In fluid connection with the reagent zone is a test zone containing immobilized molecules of the specified analyte. Preferably, in fluid connection with the test zone is a control zone containing an indicator that changes color when wetted by the sample and a liquid sink zone to absorb excess liquid in the sample.

Abstract: Disclosed is a diagnostic device for the colorimetric detection of an analyte in a test fluid. The device is a dry reagent layer which is overcoated with a transparent, fluid permeable membrane. The membrane is made up of a combination of a water dispersible and a water soluble polymer. The membrane may contain a surfactant and a thickener.

Abstract: Disclosed is a device and method for carrying out an assay for an analyte in a fluid test sample by immunochromatography. The device involves a strip having a non-porous receiving member of a hydrophobic material in direct fluid communication with a reagent region of an absorbent material through which the fluid test sample can flow by capillarity. By applying the fluid test sample to the non-porous hydrophobic receiving member rather than directly to the absorbent material the reliability of the assay is enhanced.

Abstract: A dry phase reagent test strip for measuring the concentration of an analyte in a biological fluid includes a colored indicator whose hue indicates a calibration of the strip. Preferably, the test strip measures the concentration of glucose in whole blood.