Abstract: A device for collecting and transporting aqueous fluid from the oral cavity to a lateral chromatographic strip for test is disclosed. The lateral chromatographic strip is placed within and extend along a cavity defined in a housing. At least one inspection site to the lateral chromatographic strip is provided to enable inspection of selected sites on the lateral chromatographic strip for test results. A porous wick material protrudes from the housing to a collection site exterior of the housing at one end and communicates to the lateral chromatographic strip at the other end. The porous wick material has particulate construction, the particles adsorbing aqueous oral fluid to transport the fluid from the mouth to the lateral chromatographic strip without substantial absorption. The particles of the porous wick material are bound together to define a continuous interstitial volume for the flow of oral fluid to be transported and are treated to be hydrophilic to the adsorbed oral fluids.

Abstract: A method of measuring an analyte, comprising a step of measuring a detectable substance by using a reaction system including a formation reaction of the detectable substance based on a chemical reaction of the analyte contained in a sample, wherein a layered inorganic compound is caused to exist in the reaction system including the formation reaction of the detectable substance, whereby high-sensitivity measurement is made possible, the detectable substance can be stabilized to improve accuracy of the measurement, a rate of a chemical reaction is increased to enable quick measurement, and high-sensitivity measurement is made possible even in a reaction system which forms an insoluble substance.

Abstract: A test device and method for determining the presence or absence of one or more analytes in a fluid sample, the test device including a support or member bearing a mark thereon, and a matrix or member containing a capture zone. In operation, an observation area in the test device becomes transparent, thereby allowing the user to view a mark that is present on a support that is disposed beneath the observation area. Typically, the mark on the underlying support is configured as a minus (?) sign. In the absence of analyte in the sample, the test device presents a negative result as a minus (?) signal. In the presence of analyte in the sample, however, the mark operates in concert with a perpendicular test line on the observation area to present a positive result as a plus (+) signal that is visible to the user.

Abstract: In a process for the quantitative optical analysis of biological cells labelled with a fluorescent dye, the sensitivity of analytical detection can be considerably improved if a masking dye, which absorbs the excitation light for the fluorescent dye and/or its emission light is added to the solution surrounding the biological cells and/or if a separating layer permeable to the solution and absorbing and/or reflecting the excitation light or the emission light is applied to a layer of the biological cells at the bottom of a reaction vessel. This process can also be used for improving the sensitivity in the quantitative optical analysis of a luminescent biological cell layer. Analogously, these process principles can also be used in receptor studies for the masking of the interfering background radiation in the quantitative optical analysis of fluorescently or luminescently labelled reaction components.

Abstract: The present invention relates to the field of synthetic polymeric microfiltration membrane materials that are fabricated to separate liquids from solids contained therein. One aspect of the invention relates to a highly asymmetric, hydrophilic microfiltration membrane with high surface porosity. The membrane is rendered hydrophilic through co-casting the sulfone polymer with a hydrophilic polymer, such as polyvinylpyrrolidone. The membranes of the invention are highly useful in testing devices for the quick detection of properties or components contained in liquid samples, such as diagnostic applications, as well as for other filtration applications that demand relatively large pore sizes, thick membranes, high asymmetry, and/or high lateral wicking speeds.

Abstract: Hematocrit in a blood sample is visualized by separating blood plasma from red blood cells in the blood sample on an absorbent substrate provided with a blood plasma soluble dye. Methods and devices to achieve the visualization are described.

Abstract: An electrochemical test device is provided for determining the presence or concentration of an analyte in an aqueous fluid sample. The electrochemical test device includes a working electrode and a counter electrode made of an amorphous semiconductor material. The working electrode is overlaid with a reagent capable of reacting with an analyte to produce a measurable change in potential which can be correlated to the concentration of the analyte in the fluid sample. The test device optionally contains a reference electrode made of an amorphous semiconductor material having a reference material on the reference electrode. The test device electrodes can be constructed on a flexible film substrate, such as a polymeric film or a metal foil coated with a non-conductive coating.

Abstract: In a process for the quantitative optical analysis of fluorescently labelled biological cells 5, a cell layer on a transparent support at the bottom 2 of a reaction vessel 1 is in contact with a solution 3 containing the fluorescent dye 4. The sensitivity of analytical detection can be considerably improved if to the fluorescent dye 4 already present in addition a masking dye 9, which absorbs the excitation light 6 for the fluorescent dye 4 and/or its emission light 7, is added to the solution 3 and/or if a separating layer 10 permeable to the solution and absorbing and/or reflecting the excitation light 6 or the emission light 7 is applied to the cell layer at the bottom 2. This process can also be used for improving the sensitivity in the quantitative optical analysis of a luminescent biological cell layer. The separating layer 10 must in this case be composed such that it has a high power of reflection for the luminescent light 11.

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: An electrochemical test device is provided for determining the presence or concentration of an analyte in an aqueous fluid sample. The electrochemical test device includes a working electrode and a counter electrode made of an amorphous semiconductor material. The working electrode is overlaid with a reagent capable of reacting with an analyte to produce a measurable change in potential which can be correlated to the concentration of the analyte in the fluid sample. The test device optionally contains a reference electrode made of an amorphous semiconductor material having a reference material on the reference electrode. The test device electrodes can be constructed on a flexible film substrate, such as a polymeric film or a metal foil coated with a non-conductive coating.

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 of measuring an analyte using a dry analytical element which comprises, a process of supplying a measuring reagent solution to the anlaytical element comprising at least a hydrophilic polymer layer and a microporous layer having a surface rendered hydrophilic and having a blood cell-separating ability laminated onto a water-impermeable support and not containing the measuring reagents to which a liquid sample has been supplied and thereby reaction occuring, and a process of measuring the analytical element wherein the reaction occurred by an optical means. According the above method, the shelf life of the analytical element is greatly improved. Besides, since the measuring reagnts used in the conventional wet analysis can be used, it is not necessary to develop analytical elements for each measuring item. Moreover, one kind of analytical element can be applied to many items.

Abstract: The present invention relates to an interactive system comprising at least one active surface of plastic from monomers containing at least one structural element derived from a carbon dioxide (A), and at least one substance associated to a linker with at least one structural element (B) capable of establishing a hydrogen bond, and involving an interaction between the structural elements (A) and (B). That interactive system is suitable for presenting and eliminating substances in liquids.

Abstract: The assay devices, assay systems and device components of this invention comprise at least two opposing surfaces disposed a capillary distance apart, at least one of which is capable of immobilizing at least one target ligand or a conjugate in an amount related to the presence or amount of target ligand in the sample from a fluid sample in a zone for controlled fluid movement to, through or away the zone. The inventive device components may be incorporated into conventional assay devices with membranes or may be used in the inventive membrane-less devices herein described and claimed. These components include flow control elements, measurement elements, time gates, elements for the elimination of pipetting steps, and generally, elements for the controlled flow, timing, delivery, incubation, separation, washing and other steps of the assay process.

Abstract: Disclosed is a method for quantifying cholesterol in HDL, which does not require complex fragmentation and separation operations, and by which the HDL cholesterol in test samples containing HDL and other lipoproteins such as low density lipoprotein (LDL), very low density lipoprotein (VLDL) and chylomicron (CM) may be quantified selectively, simply and accurately. The method for quantifying cholesterol in high density lipoprotein comprises a first step of erasing cholesterol in lipoproteins other than high density lipoprotein in a test sample, and a second step of adding a surfactant which specifically acts on high density lipoprotein to the product of the first step and enzymatically quantifying cholesterol in high density lipoprotein.

Abstract: An assay device and method for measuring the concentration of HDL-associated cholesterol in a blood-fluid sample are described. The assay design is such that removal of non-HDL lipoproteins from a sample and assay of HDL cholesterol in the sample occur without interruption of the assay. The device also prevents interference by reagents used for the HDL assay with other assays carried out on the same sample.

Abstract: The invention concerns an analytical device containing at least two components in which at least two of the components are joined together with the aid of an adhesive, which is characterized in that the adhesive contains an adsorptive material. The invention additionally concerns the use of adhesives which contain adsorptive material to manufacture analytical devices.

Abstract: Described is a method for discriminating complex biological samples using an array of discrete biological sensing elements immobilized onto a solid support in which constituents bound to the sensor array is directly determined by measuring the mass increase on the surface; data analysis of said method is performed using neutral network or statical based pattern recognition techniques. In a preferred embodiment the liquid sample is tested for the presence of soluble constituent(s) by contacting said sample with said sensor array under specific conditions, removing unbound sample constituent(s), determining the mass increase on the surface and comparising said mass increase data with a reference standard using pattern recognition software.

Abstract: This invention provides novel assays that are prognostic and/or diagnostic for atherosclerosis or risk of atherosclerosis. It was discovered that high density lipoprotein (HDL) or components thereof can prevent the oxidation of lipids (e.g. lipids present in LDLs) and can also repair (reduce) already oxidized lipids and thereby reduce the inflammatory response associated with and characteristic of atherosclerotic plaque formation. Moreover it was a discovery of this invention that individuals vary in the ability of their HDL to afford such protection. Thus an assay of HDL protective and/or repair activity provides a highly effective assay for risk of atherosclerosis and its associated pathologies and such assays are provided herein.

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: Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, non-biological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc.

Abstract: A test device and method for determining the presence or absence of an analyte in a fluid sample, the test device including a support bearing a mark thereon, and a matrix defining an axial flow path. In operation, an observation area in the test device becomes transparent, thereby allowing the user to view a mark that is present on a support that is disposed beneath the observation area. Typically, the mark on the underlying support is configured as a minus (?) sign. In the absence of analyte in the sample, the test device presents a negative result as a minus (?) signal. In the presence of analyte in the sample, however, the mark operates in concert with a perpendicular test line on the observation area to present a positive result as a plus (+) signal that is visible to the user.

Abstract: Devices and methods for utilizing dry chemistry dye indicator systems for body fluid analysis such as glucose level in whole blood are provided by incorporating a porous membrane with a skin side which enables separation of whole blood and visually reading the indicator without removing the red blood cell portion of the blood from the membrane. The devices also enable visual reading of the indicator by use of a membrane or matrix which provides separation of whole blood in a lateral flow of the blood through the matrix from the input area to a test area of the matrix. The devices also provide for microtitration of fluid samples in fixed volumetric openings containing indicator reagent. Another aspect of the device provides a determination of hematocrit level in whole blood in combination with indicator indication of analyte concentration which can be compensated for the hematocrit level. The devices provided are low cost.

Abstract: A method of broad screen detection, competitive dye desorption from a solid adsorbent, is described for quantifying the presence of a molecule or target analyte in the vapor phase, in solution, or eluted from a solid. In the function of an analytical element for implementing the competitive dye desorption method of the invention, dye or dye-precursor molecules adsorbed on the surface of an adsorbent are caused to desorb through the adsorption of the target analyte on the adsorbent. The desorbed dye or precursor is made detectable through sequestering of a radiation detectable species in the device of the invention. Such detection may occur, e.g., through absorption or emission of radiation in regions of the spectrum extending from the ultra-violet through the visible and into the infra-red regions. In one aspect of the invention, these processes occur within a multi-layer analytical element, in which the functions of the device may be executed by different layers.

Abstract: Methods for making reagent test strips are provided. In the subject methods, a test strip precursor made up of an elongated support material having a planar surface and a narrow stripe of reagent material positioned along its central axis is cut according to an inter-digitating pattern to produce the plurality of reagent test strips. The initial precursor material may be a tape or in the form of a card. Also provided are the reagent test strips produced by the subject methods and kits that include the same. The subject reagent test strips and kits find use in analyte detection and/or concentration determination assays.

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 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: The invention concerns an analytical element for the determination of an analyte containing in or on material which enables liquid transport between zones, a sample application zone and a detection zone located downstream thereof, wherein the detection zone contains a partner 1 of a specific binding pair 1 immobilized in such a manner that it is able to bind to partner 2 of the specific binding pair 1 which is not the analyte when it contacts it, wherein a labelled partner 1 of a specific binding pair 2 is present upstream of the detection zone impregnated on a material such that it can be detached by liquid and is able to bind to partner 2 of the specific binding pair 2 which is not the analyte when this contacts it as well as a method for the determination of an analyte using this analytical element.

Abstract: The invention concerns a device for the capillary transport of a liquid between two opposite, essentially planar layers, in which the two layers are arranged parallel to one another at such a distance that there is a capillary-active gap between the two layers, wherein at least one of the two layers contains at least two discrete adjacent parts and capillary-active transport of the liquid is possible beyond the common boundary of the parts that lie in one layer.

Abstract: The invention relates to devices and methods for carrying out quantitative fluorescence immunoassays using evanescent field excitation. Light from at least one light source is directed onto the boundary between two media which have differing refractive indices. The light source emits practically monochromatic light with a wavelength suitable for exciting a marking substance. The light is directed onto a boundary surface disposed between an optically transparent base plate, the refractive index of which is greater than that of the material above the boundary surface, and a receiving region for the sample. The receiving region is covered with a covering plate on the side disposed opposite the base plate, there being arranged between the base plate and covering plate at least one functional layer. A detector for detecting the fluorescent light is disposed on the same side of the base plate as the light source.

Abstract: The present invention is directed to a novel method for measurement of glycated hemoglobin, as well as assay methods and processes that can be used outside the medical laboratory setting to determine the fraction of total hemoglobin that is glycated.

Abstract: A method of measuring an analyte, comprising a step of measuring a detectable substance by using a reaction system including a formation reaction of the detectable substance based on a chemical reaction of the analyte contained in a sample, wherein a layered inorganic compound is caused to exist in the reaction system including the formation reaction of the detectable substance, whereby high-sensitivity measurement is made possible, the detectable substance can be stabilized to improve accuracy of the measurement, a rate of a chemical reaction is increased to enable quick measurement, and high-sensitivity measurement is made possible even in a reaction system which forms an insoluble substance.

Abstract: An electrochemical test device is provided for determining the presence or concentration of an analyte in an aqueous fluid sample. The electrochemical test device includes a working electrode and a counter electrode made of an amorphous semiconductor material. The working electrode is overlaid with a reagent capable of reacting with an analyte to produce a measurable change in potential which can be correlated to the concentration of the analyte in the fluid sample. The test device optionally contains a reference electrode made of an amorphous semiconductor material having a reference material on the reference electrode. The test device electrodes can be constructed on a flexible film substrate, such as a polymeric film or a metal foil coated with a non-conductive coating.

Abstract: A method of measuring an analyte, comprising a step of measuring a detectable substance by using a reaction system including a formation reaction of the detectable substance based on a chemical reaction of the analyte contained in a sample, wherein a layered inorganic compound is caused to exist in the reaction system including the formation reaction of the detectable substance, whereby high-sensitivity measurement is made possible, the detectable substance can be stabilized to improve accuracy of the measurement, a rate of a chemical reaction is increased to enable quick measurement, and high-sensitivity measurement is made possible even in a reaction system which forms an insoluble substance.

Abstract: A method of measuring an analyte, comprising a step of measuring a detectable substance by using a reaction system including a formation reaction of the detectable substance based on a chemical reaction of the analyte contained in a sample, wherein a layered inorganic compound is caused to exist in the reaction system including the formation reaction of the detectable substance, whereby high-sensitivity measurement is made possible, the detectable substance can be stabilized to improve accuracy of the measurement, a rate of a chemical reaction is increased to enable quick measurement, and high-sensitivity measurement is made possible even in a reaction system which forms an insoluble substance.

Abstract: A diagnostic testing kit for collection of fluid samples comprising a reservoir cup insertable into a container vessel. Fluid placed in the cup is communicated to reactive test strips located in a separation cavity between the cup and the container vessel when assembled. The test strips have a reactive agent impregnated in them that reacts to specific substances in the fluid and provide a visual result through the sidewall of the container vessel to the user. An optional alarm is provided to show minimum and maximum test times.

Abstract: A multilayer analytical element for determining a level of an analyte on a substrate and adapted for use with hydrogen peroxide and an affinity-enzymatic compound of formula A-C-B, wherein A is a detecting agent having affinity for the analyte, B is an enzymatic visualizing agent consisting of peroxidase and C is a binding agent linking the detecting and visualizing agents together. The multilayer analytical element of the invention comprises a solid support and a hydrophilic layer thereon, the hydrophilic layer being formed of gelatin, polyvinyl alcohol or a mixture thereof and containing a developing agent and a hydrophobic color-producing agent in a total amount of 5 to 30 weight %, the developing agent and the color-producing agent being present in a weight ratio of 1:0.3 to 1:3.0.

Abstract: An immunoassay element for quantitatively analyzing a macromolecular antigen by determining the change in enzymatic activity caused by a reaction between the macromolecular polymer antigen and an enzyme-labelled antibody. 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 containing a fragmenting enzyme for further fragmenting the diffusible material into a lower molecular weight product. Also provided is a process for quantitatively analyzing a macromolecular antigen in a sample by the use of the immunoassay element.

Abstract: A holographic sensor comprising a thin film polymer matrix that undergoes a change in response to a substance to be sensed, the matrix containing within its volume a set of two or more holographic recordings, each recording providing a holographic image when the sensor is illuminated, wherein the presence or appearance of each image is visible to the eye as a function of the response of the sensor to the substance to be sensed. The images provide the dynamic range of the sensor. Such a sensor can be used to provide a visible image that changes or appears to the eye in response to an analyte.

Abstract: A visual blood glucose test strip has two membranes that each incorporate a reagent that reacts with glucose in a blood sample applied to the membranes to cause a color change. One of the membranes also includes an inhibitor and a dye. A blood sample applied to the strip causes the two membranes to form two different colors. Comparing the colors to a calibrated color chart permits a user to determine the glucose concentration in the blood sample.

Abstract: The present invention relates to a sintered porous polymeric material useful as membrane in an analyte detection device, such as a lateral flow device, flow through device, or a dipstick device. The invention encompasses an analyte detection device that comprises such a sintered porous polymeric material and method of analyte detection using such a device. Specific sintered porous polymeric materials encompassed by the invention are surface activated and further coated with one or more layers of a variety of materials.

Abstract: The present invention provides a measurement chip for a surface plasmon resonance biosensor, which comprises a transparent substrate, a metal membrane located on the transparent substrate and an organic silicon membrane immobilized on the metal membrane and in which the organic silicon membrane is immobilized on the metal membrane via a functional group capable of binding with atoms on the surface of a metal. The measurement chip for a biosensor of the present invention can easily be produced. Using the measurement chip of the present invention, a target substance can be measured with good sensitivity, even if only a small amount of physiologically active substance is immobilized.

Abstract: An improved rapid diagnostic device, assay and multifunctional buffer reagent are provided for the detection of a target analyte in a fluid test sample. The 2-step assay utilizes a dual component flow-through device comprising a test unit and a post-filter unit capable of receiving the fluid sample and multifunctional buffer, respectively. The test unit comprises a reaction zone containing immobilized capture reagent that can specifically bind to the target analyte, an absorbent zone supporting the reaction zone, and optionally, a blood separation zone in lateral fluid communication with the reaction zone. The post-filter unit comprises a label zone permeated with a dried indicator reagent which is capable of being placed in transient fluid communication with the reaction zone of the test unit during the assay procedure. The rapid diagnostic assay system reduces the number of assay reagents, method steps and time required for performance compared to other conventional assays.

Abstract: A visual blood glucose test strip has two membranes that each incorporate a reagent that reacts with glucose in a blood sample applied to the membranes to cause a color change. One of the membranes also includes an inhibitor and a dye. A blood sample applied to the strip causes the two membranes to form two different colors. Comparing the colors to a calibrated color chart permits a user to determine the glucose concentration in the blood sample.

Abstract: A test strip having the capability of separating blood cells from whole blood, wherein it has a porous reagent layer comprising beads, an inorganic gel and a reagent that causes a detectable reaction with a substance to be detected, and a substrate that supports the reagent layer, wherein the beads are adhered to each other with the inorganic gel, and interstices are formed between the beads to trap a solid. The test strip can thus be used for separating blood cells from a whole blood including blood cells and plasma and detecting a substance to be detected, such as glucose, contained in plasma. The use of the test strip allows the measurement of a substance to be detected even by measurement of a transmitted light, the exhibition of good oxygen permeability, and thus can be used for measuring a substance to be detected with improved accuracy.

Abstract: A test strip for conducting a lateral flow assay for detection of an analyte in a sample that contains cells and fluid is provided, as well as methods for making and using the test strip. This test strip is commercially usable, for example, in a diagnostic device at a point of care for detection of analytes in whole blood.

Abstract: A fluidic medical diagnostic device permits measurement of analyte concentration or a property of a biological fluid, particularly the coagulation time of blood. The device has at one end a sample port for introducing a sample and at the other end a bladder for drawing the sample to a measurement area. A channel carries the sample from the sample port to the measurement area, and a stop junction, between the measurement area and bladder, halts the sample flow. The desired measurement can be made by placing the device into a meter which measures a physical property of the sample—typically, optical transmittance—after it has interacted with a reagent in the measurement area.

Abstract: By forming a detection-membrane with a light reflective layer in which the detection-membrane is a multilayer construction with a protective layer, a detection-membrane can be provided which is able to be used favorably within an optical sensor, will suffer no reduction in mechanical strength as a result of external factors such as physical pressure, high temperature, high humidity or the like, and will cause no deterioration in the characteristics of an optical sensor, and an optical sensor which utilizes such a detection-membrane can also be provided.

Abstract: An analytical or preparatory microfluidic system is disclosed which generally comprises a base unit comprising a first adapter interface array; a first adapter plate selected from a set of a plurality of different adapter plates, wherein the first adapter plate comprises a base unit interface array that is complementary to the first adapter interface array, and a first substrate interface array, wherein the first adapter plate is removably coupled to the base unit such that energy passes from the base unit to the adapter plate through the first adapter and base unit interface arrays. The system further comprises a first microfluidic substrate selected from a set of a plurality of different microfluidic substrates, the first microfluidic substrate comprising a plurality of mesoscale channels disposed therein and a second adapter interface array, wherein the second adapter interface array is complementary to the first substrate interface array.

Abstract: A detector for monitoring an analyte includes an analyte-sensing composition. The analyte-sensing composition has a visible color intensity or emission intensity (e.g., fluorescence intensity) that changes as the analyte concentration contacting the detector changes. The intensity changes can be visible to the human eye, or identified by an instrument. The analyte can include carbon dioxide, a volatile amine or a volatile carboxylic acid.