Abstract: A straw for the conservation of small quantities of substances, notably biological substances, comprising a segment of tube fitted internally at one end with closure means comprising a two-part plug comprising a microporous and hydrophobic membrane and an insert through which there is a substantially coaxial orifice.

Abstract: Disclosed are an immunoassay device which comprises a labeled substance dotting portion and a specimen dotting portion provided thereon, and an immunoassay method using the device.

Abstract: The present invention provides a well-less filtration device that includes a pre-filter layer; a support layer; and at least one layer of solid phase extraction medium disposed between the pre-filter layer and the support layer. At least a portion of the pre-filter layer, support layer and solid phase extraction medium are ultrasonically welded together to form a pattern of filter cells and land areas with the land areas being disposed between the filter cells. The filter cells of the device may be arranged to conform to a standardized array format.

Abstract: A multiple analyte assaying device includes a casing having a pocket portion adapted to capture or contain a predetermined volume of fluid specimen to be assayed. Disposed within the casing is a sample receiving pad and one or more reagent test strips. The pocket portion of the casing includes a feed element having multiple feed inlets, or alternatively, a single feed slot. The feed element provides pressure against the sample receiving pad. The pressure against the pad and a small size of the inlet or inlets are effective in controlling a rate of fluid release of the specimen to the sample receiving pad. The casing includes observation windows or alternatively a clear plastic view area for enabling observation of reagent zones of the test strips. The device is structured and adapted to enable a technician to capture the appropriate volume of fluid specimen in the pocket portion by submerging or dipping a portion of the device into a fluid-filled collection container for a brief period of time.

Abstract: In a method for recognizing the faulty positioning of an optically evaluatable test strip in a device for measuring a substance in a liquid, especially for blood sugar determination, the fluid to be investigated is applied to a test field (24) of a test strip (20) and the change in the reflection or transmission ability of the test field (24) thereby effected is captured and evaluated. A measuring field (16) of the measuring device associated with the test field of the test strip is divided into at least two measuring areas which, with respect to the insertion direction of the test strip, are arranged behind one another and are separately sensed. The test strip (20) has at least in the area lying in front of the test field (24), with respect to the insertion direction zones (28, 29) arranged behind one another and of different reflection or transmission abilities.

Abstract: A swab assembly (10) comprises an external housing (11) formed from two interengageable housing parts (12, 13). A hollow tubular member (14) having swab material (16) at one end is attached to one housing part (12) at the other end. The Interior of the tubular member (14) is closed off with a seal member and contains a suitable reagent (18) which is held in spaced disposition from the swab material by capillary action. When the assembly is to be used, the two housing parts (12, 13) are separated revealing the inner tubular member (14) and the swab material (16) can be utilised to collect a sample. If it is desired to dispense reagent (18) onto the swab material (16) prior to or after collection of the sample, the tubular member (14) can be deformed in the region of a seal (17) to separate the tubular member from the housing part (12) thereby allowing the reagent (18) to flow onto the material (16).

Abstract: Technological preposition of the present invention is a liquid processing method making use of a pipette device which sucks a liquid containing a target high molecular substance from inside of a vessel through a chip detachably set on a sucking port or a discharging port of a liquid sucking/discharging line and transfers this liquid or target high molecular substance to the next target processing position for the purpose to execute such works as quantifying, separating, taking out, pipetting, clarifying condensing, and diluting a liquid or a target high molecular substance contained in a liquid and also such works as extracting, recovering, and isolating the target high molecular substance by means of sucking and discharging a liquid with a pipette device and controls by a magnetic body over magnetic particles and/or a filter combined according to the necessity, and the chip can isolate the target high molecular substance by having the substance attracted onto magnetic particles or with a filter set on each c

Abstract: A test strip for confirming a desired proportion of components in dialysate, including a first medium capable of indicating the concentration of bicarbonate ion, and a second medium capable of indicating the concentration of glucose. The test strip defines a first region impregnated with the first medium, and a second region impregnated with the second medium. The test strip optionally includes a third medium capable of indicating the pH of the dialysate. The third medium is impregnated at a third region on the test strip. Alternatively, the test strip comprises a bicarbonate test pad attached to the first region, a glucose test pad attached to the second region, and optionally a pH test pad attached to the third region. The glucose test pad is impregnated with the first medium, the glucose test pad is impregnated with the second medium, and the pH test pad is impregnated with the third medium.

Abstract: Invention performs an assay to determine presence or quantity of specific analyte in fluid sample. Representative device has two separate flow paths established sequentially in device with a single user activation step. First flow path delivers sample, and conjugate soluble binding reagents to solid phase. If analyte is present, an analyte:conjugate complex is formed and immobilized. Sample volume delivered by first path determined by absorbent capacity of solid phase, and not by amount of sample added to device. User need not measure sample volume. Sample/conjugate mixture is prevented from entering second flow path because capillary and surface energy of second flow path prevent it from being wetted by this mixture. Second flow path allows wash reagent to remove unbound conjugate and sample from solid phase to the absorbant, and optionally deliver detection reagents.

Abstract: In the method moving a sample substance by means of a sample feeder (26) form a sample pickup site to a delivery site (20) of a sample processor (10), the invention proposes fitting the sample feeder (26) with at least one porous material element having a pore size such that the sample substance shall be kept in the liquid phase in the porous material at least during sample pickup by the sample feeder (26) and during sample delivery to the sample processor (10).

Abstract: Apparatus and methods for modulating flow rates in microfluidic devices are provided. The methods involve modulating downstream pressure in the device to change the flow rate of materials in an upstream region of the device. Such methods include electrokinetic injection or withdrawal of materials through a side channel and the use of an absorbent material to induce wicking in the channel system. The apparatus provided includes a prefabricated wick in the device to provide for flow rate control. Additional methods for determining velocity of a particle and cell incubation time are also provided.

Abstract: Multi-sectioned fluid delivery devices with sensor membranes for use in detection of target molecules in gas or liquid samples are provided.

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: An assay device comprises a sample-collecting wick made from non-woven fabric material laminated to plastics sheet. Preferably, the fabric is a 30:70 blend of viscose and polyester, and has a fibrous structure in which more than two thirds of the fibers run substantially parallel to the intended direction of liquid flow in the wick.

Abstract: A device for detecting and enumerating microorganisms in a sample substance employs an external container and an internal container inserted into the headspace of the external container. The sample is mixed with liquid growth media in the internal container. Gases generated from the metabolic activity of the microorganisms during incubation expand to the headspace of the sealed external container and interact with an indicator located at a transparent section of the external container. Changes of the indicator are read by an external real time photometer that generates time patterns for analysis. These patterns indicate the presence or absence of microorganisms and assess the level of contamination in the original sample.

Abstract: An immunoassay method comprising bringing an immobilized phase comprising, at different positions on a water-absorbable base material, at least two first immunity substances capable of specifically binding with at least two kinds of assay target substances selected from the group consisting of verotoxin-producing Escherichia coli, verotoxin and human hemoglobin contained in a test sample, into contact with a test sample and a liquid containing labeled immunity substances each comprising a second immunity substance that is labeled with colored particles and capable of binding with said assay target substance, thereby to form an assay target substance-labeled immunity substance complex and to bind said complex with respective first immunity substances at the immobilized phase.

Abstract: A chromatographic strip positive readout binding assay device and method suitable for quick, sensitive and reliable field testing for small molecules such as environmental contaminants, drugs of abuse, therapeutic drugs and hormones. The detectable label is not attached to either the analyte or to the analyte receptor. Low affinity binding pairs can be used in the positive readout binding assay.

Abstract: A immunochromatographical test device including a cap, an absorbent pad, a membrane, a test strip, a holder, and a housing is disclosed. The housing contains the membrane and the test strip which contains immunoreagents. Secured to the holder is the absorbent pad which contains the sample to be tested. The cap fits over the holder and the holder fits within the housing. When the absorbent pad contacts the membrane, the membrane indicates that a proper amount of the sample has been collected. When the absorbent pad contacts the test strip, a reaction, if any, can be observed via a window formed within the housing.

Abstract: A test card for drugs of abuse has a thin flat member having the size and shape of a business card. A plurality of immunoassay test strips extend longitudinally from top to bottom at the card and are fastened side by side in parallel on one or both sides of the test card within the outline of the card. Each test strip is reactive to provide a visual indication in response to a particular drug of abuse. The test card thus provides for the simultaneous detection of multiple analytes. Processes are also disclosed for making the drug test card with test strips on one and both sides of the card.

Abstract: The present invention is directed to a method of detecting prostatitis comprising obtaining an expressed prostatic secretion from a patient; contacting a device having diagnostic test reagents to the expressed prostatic secretion, the diagnostic test reagents reacting with the expressed prostatic secretion to produce a change in the device; reading the change in the device to produce a positive or negative experimental test result, wherein the experimental test result is positive when the experimental test result is pre-determined to correspond with a number above 10 for the number of white blood cell per high powered field and the experimental test result is negative when the experimental test result corresponds with a number of 10 or less for the number of white blood cell per high powered field; and determining presence of prostatitis with the positive experimental test result and the absence of prostatitis with the negative experimental test result.

Abstract: An apparatus for measuring the ability of ameboidally mobile cells to migrate has a deposit of active substance in the form of a plate, a membrane filter disposed on the deposit and one or more vessels on the filter. The vessel or vessels have a base opening, for a liquid which contains ameboidally mobile cells. The base opening in the vessel bears against the membrane filter. A surface area of the membrane filter is at least 1.6 times as large as the area of the base opening in the vessel.

Abstract: A saliva testing and confirmation device generally includes an expresser cup adapted to receive and compress a foam collection swab pressed into the cup. The swab includes a sponge or foam portion capable of absorbing a fluid specimen such as saliva, and a generally rigid handle for facilitating manipulation thereof. The device also includes a testing and confirmation platform integral with the expresser cup. A channel or groove in the cup is provided for directing a flow of expressed fluid from the expresser into both a test well and a confirmation well. A lateral flow reagent test strip, in fluid communication with the test well may be encased in the platform and partially revealed for analysis of test results. The confirmation well includes a fluid tight cap having a tamper evident seal.

Abstract: The invention concerns a method for the immunological determination of an analyte on a chromatographic test strip containing one or several absorbent matrices on a carrier material which are in liquid-transferring contact with one another wherein the matrices form an application zone at one end and a suction zone at the other end of the carrier material, a conjugate zone in the application zone or adjoining the application zone which contains a visually detectable, particle-labelled analyte binding partner, a chromatographic zone adjoining the conjugate zone and a capture zone between the chromatographic zone and suction zone wherein the capture zone contains solid phase-bound binding partners for the analyte or for an unlabelled analyte-specific binding partner by applying the analyte solution to the application zone and measuring the bound label in the capture zone as a measure of the analyte characterized in that a fluorescent dye is applied to the application zone or to a matrix between the application zo

Abstract: A method for the detection of substances contained on textile fibers or other natural or synthetic polymers is disclosed. The contained substances are identified with immunochemical methods, where the immunochemical reaction can occur on the fiber or polymer. The method is especially suitable for the determination of substances that can act as allergens.

Abstract: Devices for performing active biological operations utilize various structures to advantageously collect and provide charged biological materials to an array of microlocations. An active biological matrix device includes an array of unit cells, each unit cell including a variable current control element, a select switch, and a return electrode. The output of the select switch is preferably adapted to contact a conductive solution including charged biological materials. The return electrode is preferably connected to a second potential and adapted to contact the conductive solution. In the presence of the conductive solution, current is provided between the return electrode and the output of the select switch. The variable current control element includes a control element that is adapted to receive a first control signal via, preferably, a first column line. The select switch includes a control element that is adapted to receive a second control signal via, preferably, a first row line.

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: 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: 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: 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 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: 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: 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: A genetic testing system includes a miniaturized thermal cycling device and an integrated, unitary microchip based detection device with microfluidic controls, on chip electronics. The genetic testing system further uses dipped or coated polymeric materials on processed silicon as a means to facilitate amplification chemistry.

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: A apparatus for assaying glycated proteins and other analytes in biological samples such as blood, in which a sample is presented to the apparatus, includes an inlet port between moveable between first and second inlets, such that the inlet can be brought into liquid communication with each inlet in turn. The inlet port accommodates a filter or binder. The apparatus also includes a microprocessor operable via a key pad, at least one light emitter and at least one light detector, a display and driver, and an A to D converter, and is operatively connected to a power source.

Abstract: A straw for the conservation of small quantities of substances, notably biological substances, comprising a segment of tube fitted internally at one end with an insert through which there is a substantially coaxial orifice. A plug can be accommodated in the insert.

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: 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 calorimetrically 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: Arrays of polymeric targets stably associated with the surface of a rigid solid support are provided. In the subject arrays, the polymeric targets are arranged at least according to size. The polymeric targets of the subject arrays are generally biopolymeric compounds, e.g. nucleic acids and proteins, where ribonucleic acids and proteins are the preferred polymeric targets. The subject arrays find use in a variety of different applications, and are particularly suited for use in high through gene expression analysis applications.

Abstract: A culture monitor (10) for microbiological testing of a liquid sample includes a housing having a liquid inlet (30) and a liquid outlet (32, 34), and a liquid sample filtration means inside the housing between the liquid inlet (30) and the liquid outlet (32, 34). The liquid sample filtration means including a filter medium (16) so that a liquid sample entering the housing through the liquid inlet (30) passes through the filter medium (16), with microorganisms present in the liquid sample being retained on the filter medium (16) and spent liquid or filtrate passing through the filter medium (16). A reservoir (53) is provided in the housing downstream of the liquid sample filtration means relative to the liquid inlet (30), with a volume of a rehydration agent for a dehydrated culture medium being provided in the reservoir (53), or the reservoir (53) being adapted to retain during filtration, as a rehydration agent, a portion of the filtrate.

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: 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: A laboratory device is disclosed for growing microorganisms in a multi-compartment format, which provides convenience for dispensing, inoculation, incubation and harvesting when it is used for liquid cultures. The device includes a solid frame having formed within it a plurality of culturing compartments defined by solid side-walls built in the frame and plastic film and an assembly comprising an absorbing substrate and two non-absorbing fiber pads in each of the culturing compartments. These elements are generally rectangular in shape and the device can be sized to stack for incubation and storage. An access port and a series of apertures on the frame arranged a specific configuration permit introduction of liquid such as a liquid growth medium or a sample suspension into the culturing compartments simultaneously and equally.

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: A method and an apparatus for determining the concentration at which a growth-altering agent has an appreciable effect on the growth of a target microorganism are provided.

Abstract: An automated nucleic acid compaction device for analyzing and compacting a nucleic acid complex into unimolecular nucleic acid particles. Broadly, the device includes a container support and agitation system; a measuring and testing system; and a dispensing system; all controlled by a control system. The control system controls the support and agitation system and the dispensing system based either on a predetermined formulation or by analysis of feedback data provided by the measuring and testing system. In a preferred embodiment, the device is a real-time measuring and mixing instrument operating in a closed loop system. The preferred embodiment also comprises a monitoring system including a submersible probe which is positioned in the batch solution to provide data to a controller. Once a desired level of nucleic acid compaction is reached, as detected by the monitoring system, the controller stops the dispensing and mixing agitating systems.

Abstract: The invention is an improved single-step test device for detecting the presence of a pre-selected analyte in a urine stream. The device includes a hollow rectangular outer casing and an assay material disposed within co-joined upper and lower sections of the casing. The outer casing includes a urine inlet port; a viewing window in the upper section; at least the upper section consisting of transparent material; and may also include at least one drainage vent spaced about the urine inlet port. The assay material is a sorptive material including: a urine sample application region adjacent to, and in fluid communication with the urine inlet port; a capture region adjacent to the viewing window; and a fluid flow path for transporting a liquid sample between the urine sample application region and the analyte capture region. The flow of urine in the fluid path is observable through the transparent upper section for confirming a test is operative.

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 an insertable test strip containing a reagent enabling detection of the analyte of interest.

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 test device for detecting or determining an analyte in a test solution includes an absorbent material having separate contact, competitive binding, and measurement portions. The contact portion is positioned for contact with and uptake of the test solution. The competitive binding portion has a binding material for the analyte non-diffusively bound thereto. The measurement portion has a receptor for the analyte and marker-encapsulating liposomes non-diffusively bound thereto. In a method for using the test device, a solution containing the analyte and the analyte-liposome conjugate is allowed to traverse the absorbent material from the contact portion through the competitive binding portion and on through the measurement portion of the absorbent material. The amount of marker in the measurement portion of the absorbent material, following traversal by the test solution, is then determined as a measure of the analyte in the sample.