Abstract: A method and device are provided for the semi-quantitative and quantitative determination of an analyte in a sample. A non-competitive trap which can bind unreacted labelled receptor to analyte but has virtually no binding capabilities to receptor in the presence of analyte is used. Labelled receptor:analyte complex is trapped in a second trap. The relative amounts of unbound receptor in the non-competitive trap versus the amount of receptor:analyte complex in the second trap is a measure of the amount of analyte in the sample.

Abstract: Methods and systems for verifying the volume of a reagent dispensed into an affinity assay vessel are described. In one embodiment, a method is for verifying the volume of a reagent dispensed into an affinity assay vessel described in which a fluid sample is deposited into a vessel that includes a reaction chamber and a volume determination reference point. The reaction chamber further includes a test strip. According to one embodiment, the dispensed fluid is agitated to promote contact between the fluid and a test strip disposed within the reaction chamber. The relative positions of the volume determination reference point and an edge of the meniscus of the dispensed fluid are then determined such that the meniscus of the dispensed fluid is not penetrated. The volume of the dispensed fluid is determined from these relative positions.

Abstract: A multilayer dry immunoassay element comprising 1) a spreading layer having a sample application area and a signal read area and 2) a separate receptor layer residing on 3) a radiation-transmissive support characterized in that the spreading layer contains a light absorbing material.

Abstract: A composition, method, and test device for quantitatively determining the oxidant concentration of a test sample are disclosed. The test device includes a test pad having a suitable carrier matrix incorporating an indicator reagent composition capable of interacting with an oxidant to produce a detectable and measurable response for oxidant over a wide concentration range of oxidant. An indicator reagent composition contains: (a) an iodide salt, (b) a buffer, and (c) a water-soluble polymer, preferably a cellulose-based polymer. An indicator reagent composition is incorporated into a carrier matrix, like filter paper, to provide a test pad useful in a dry phase oxidant assay of a test sample, especially for test samples containing a high concentration of oxidant, like chlorine or a peroxide.

Abstract: An assay device for detection or determination of an analyte in a sample uses opposable components and is suitable for assay of human chorionic gonadotropin and other protein or glycoprotein hormones.

Abstract: The prevent invention relates to an integrated package-holder assay devices for detecting the presence of analyte in a sample. The device serves the dual roles of supporting and protecting an immunochromatographic assay. The device is compatible with any immunochromatographic assay format. The assay can be performed in a single apparatus for use in a laboratory or a field setting. In a specific example, the assay device is a nylon membrane formatted for an immunochromatographic assay for cotinine sealed between transparent adhesive tape and a stiff plastic strip. White tape placed over the plastic strip defined a window for observing the assay results.

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: The present invention includes a method to detect canine IgE using a canine Fc epsilon receptor (Fc.sub..epsilon. R) to detect canine IgE antibodies in a biological sample from a canid. The present invention also relates to kits to perform such methods.

Abstract: A method is disclosed for determining the presence or amount of analyte in a fecal sample. The method comprises the steps of (A) contacting the fecal sample with an extraction reagent comprised of at least one detergent and at least one buffer to form a mixture, (B) applying the mixture to an absorbent filter that is in proximity to or in contact with an immunoassay such that analyte present in the sample is transferred to the immunoassay, and (C) detecting the presence of analyte by said immunoassay. In a preferred embodiment, the immunoassay comprises a porous strip containing immunoreagents for detecting analyte.

Abstract: A test device which includes a housing having an immunochromatographic test strip therein is disclosed. The test strip is color-coded so that the presence or absence of a substance or substances in a fluid sample may be detected and identified. The strip also indicates the locations of the immunoreactions that will take place on the test strip by means of colored lines. Sample is applied onto the strip through a window and is spontaneously wicked up the test strip mobilizing a dye-microspherical antibody located in a first zone on the strip. The dye particles then move along the membrane strip by capillary action to a second zone. In the absence of specific antigen in the sample, the dye-microsphere particles attach to the antigen in the second and third zones through immunocomplexation, forming definite, visible lines. This is a negative test.

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: A testing apparatus 10 having an absorbent matrix 12, including a membrane 14 which contains a plurality of counter-ions 16. Chromoionophore (or fluorionophore)s 18 and affinophores 22 compete to carry ions into the membrane 14 and neutralize the charge of the counter-ions 16. Biological recognition molecules 42 bind to a portion of the affinophores 22 and prevent them from entering the membrane 14, thereby allowing more chromoionophore (or fluorionophore)s 18 to enter the membrane 14. The portion of affinophores 22 bound to the biological recognition molecules 42 is inversely proportional to the amount or concentration of analyte 40 occurring within the solution or medium 30. The result of this is that the color of the membrane-covered matrix changes in a manner related to the concentration of the analyte. One application of this apparatus is a strip test for prediction of ovulation.

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: An evaluating method of a testing element having an immobilized antigen or antibody on an immobilizing carrier thereof, which immobilized antigen or antibody has yet to react with another antigen or antibody, which involves contacting the testing element with a solution containing an antibody or antigen reactive with the immobilized antigen or antibody, specifically binding a labelling compound to the reactive antibody or antigen to thereby cause a color-developing reaction of the labelling compound, and determining an amount of the antigen or antibody immobilized on the testing element as a function of a level of produced color. Using this evaluation method, a quantitative determination of the immobilized antigen or antibody can be carried out, and thus the performance of the testing element for antigens or antibodies can be evaluated.

Abstract: A dry chemistry dye indicator composition provides improved shelf life, stable color indication end point and capability for a system at near normal pH. The novel dry chemistry dye indication system comprises 3-Methyl-6-(sodium sulfonate)-benzothiazolinone-(2)-hydrazone (MBTH-S). A preferred dye systems are based on the dye couple (MBTH-S) and 8-anilino-1-naphthalenesulfonate (ANS), and the dye couple MBTH-S and N-(3-sulfopropyl)analine. These dye indicator systems are used in conventional blood chemistry test strips and are particularly preferred for indication of glucose in blood.

Abstract: Methods of calculating the platelet count of an individual, by measuring the amount of a released platelet granule protein of interest in a sample of whole blood or of platelet-rich plasma from the individual, are described. The platelet granule protein of interest is either thrombospondin or .beta.-thromboglobulin. The amount of released platelet granule protein of interest in the whole blood sample or platelet-rich plasma sample is measured using an enzyme-linked immunosorbent assay; radioimmunoassay; sandwich assay; a quantitative immunochromatographic assay; or non-solid phase nephelometry. The platelet count is directly related to the amount of released platelet granule protein of interest in the sample, and can be determined from the amount of platelet granule protein of interest that is released from a known number of platelets.

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

Abstract: A method and apparatus for the quantitative determination of an analyte in a liquid employs a liquid-permeable solid medium defining a liquid flow path. The medium includes a number of reactant-containing reaction zones spaced apart along the flow path and in which reaction occurs with the analyte or an analyte derivative (e.g., a labeled analyte) to result in the formation of a predetermined product. Detector means are employed to detect analyte, analyte derivative, reactant or predetermined product in the reaction zones, the number of such zones in which such detection occurs indicating the amount of analyte in the liquid.

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 spectrophotometric assay for the detection of acetaminophen in aqueous fluids can be carried out with a dry analytical element. The element comprises a support having thereon one or more reagent layers containing a first enzyme, aryl acylamidase, to cleave the amide bond of acetaminophen to produce p-aminophenol; a second enzyme, ascorbic acid oxidase, to oxidize the p-aminophenol so that it couples to a water soluble coupling agent to form a dye that is read at 670 nm. The assay is precise, accurate on serum and plasma samples, and relatively free from significant interferences. The element also allows measurement over a broad dynamic range.

Abstract: A method of assaying a preselected volume of sample on an chromatographic strip includes providing a sample receiving reservoir. This reservoir can receive a preselected volume of sample or a preselected volume of sample and reagent. The sample receiving reservoir has an overflow outlet. A moat is communicated to the overflow outlet of the sample receiving reservoir for receiving the sample or sample and reagent when the sample receiving reservoir is full. The mixed sample or sample and reagent fill the sample receiving reservoir, and discharge the excess sample through the overflow outlet to the moat. The sample receiving reservoir having the preselected volume of sample or sample and reagent is discharged on the chromatographic strip for assay. Provision is made for adding a density adding solute which is neutral to the chromatographic strip, the density adding solute occupying the sample receiving reservoir.

Abstract: Disclosed are devices and methods for performing an assay which determines the presence or quantity of an analyte in a fluid sample by detecting binding of the analyte to at least one immobilized analyte capture reagent and washing unbound material from the immobilized analyte capture reagent. The devices and methods an elongated solid phase flow matrix, including capillary channels capable of driving capillary fluid movement, and further including (i) a first region adapted for receipt of the fluid sample, (ii) a second region at which the analyte capture reagent is immobilized, (iii) a third region for application of a wash reagent capable of removing unbound substances from the second region; and (iv) an absorbent reservoir of high volume capacity. The second region is positioned intermediate to the first region and the third region and intermediate to the absorbent reservoir and the third region. The device also includes means to detect analyte bound at the second region.

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: An apparatus in the form of a test strip is useful for determining the presence of one or more components in a fluid sample. The test strip can be used by itself or in conjunction with an associated housing assembly. The test strip provides a rapid volume, timing and temperature independent visually readable strip for the semi-quantitative detection of a component, such as an analyte.

Abstract: In a method for assaying an anticardiolipin antibody in a sample utilizing .beta.2-glycoprotein I, a polypeptide having the same amino acid sequence as domain IV of .beta.2-glycoprotein I or a polypeptide partially different therefrom but functionally equivalent thereto is used in place of .beta.2-glycoprotein I itself. According to this method, an autoantibody from patients with antiphospholipid syndrome can be accurately assayed in a simple manner.

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: The invention is directed to a non-instrumented assay giving quantitative and/or qualitative results. Specifically, the invention is directed to an assaying process wherein a first portion of binder supported on substantially the entire length of a solid is contacted with a sample suspected of containing analyte. The binder is a binder for at least the analyte. The first portion is also contacted with a tracer. The process includes contacting a second binder portion also supported on the solid with tracer. The second portion is juxtaposed to the first portion and has a known amount of analyte thereon. The amount of analyte in the sample is determined by comparing the visibility of tracer in the first and second portions. In a preferred embodiment, a third binder portion supported on the solid juxtaposed to the second portion is contacted with tracer. The third portion has a known amount of analyte thereon. The amount of analyte in the third portion is different from the amount on the second portion.

Abstract: A slide having a portion thereof provided with transparent adhesive which adheres to a test sample. The slide and adhesive may be transparent. Specific types of infection and particularly fungal infections can be detected in the test sample using immunotest-methods. In a special embodiment the adhesive slide is fashioned with a peripheral lip or well to contain a test sample and a reagent.

Abstract: Disclosed is a test cell and a method for detection of a preselected ligand in a liquid sample such as a body fluid. The test cell includes an elongate outer casing which houses an interior permeable material capable of transporting an aqueous solution and defining a sample inlet, a test volume, and a reservoir volume. The reservoir volume is disposed in a section of the test cell spaced apart from the inlet and is filled with sorbent material. The reservoir acts to receive liquid transported along a flow path defined by the permeable material and extending from the inlet and through the test volume. In the test volume is a test site which includes a first protein having a binding site specific to a first epitope of the ligand immobilized in fluid communication with the flow path. The test site can be observed through a window of the casing.

Abstract: A test device, system and method, the device composed of an elongated, toothbrush-shaped, transparent, plastic housing and a lateral-flow test strip for the detection of an analyte, such as a beta-lactam in milk, in the housing, the housing having an expansion cavity to receive expanded, liquid-contacted, absorbing material in the test strip, and to control lateral flow rate and times in the test strip.

Abstract: Methods and test devices for detecting the presence or amount of target ligand in non-competitive sandwich ligand-receptor assay processes. Antibodies which bind to the complex of ligand receptor and target ligand but do not bind significantly to the ligand receptor and which bind the target ligand with substantially less affinity than the complex are taught and their uses described. These assays can be used to eliminate the "hook" effect in non-competitive sandwich assays. Furthermore, the antibodies are selected and assay methods described so that, as a result of the assay process, no detectable response is observed due to the binding of antibody and ligand receptor in the absence of target ligand.

Abstract: A solid medium for storage of DNA, including blood DNA, comprising a solid matrix having a compound or composition which protects against degradation of DNA incorporated into or absorbed on the matrix. Methods for storage of DNA using this solid medium, and for recovery of DNA or in situ use of DNA are also disclosed.

Abstract: The method of the invention involves providing a first receptacle and a second receptacle. The first receptacle contains a sterile aqueous broth and the second receptacle contains an aqueous broth including a carbon source. The method then includes placing into the first receptacle a first support surface having a paraffin wax coating thereon and placing into the second receptacle a second support surface having a hydrophobic material coating thereon. A body specimen, such as sputum, is then introduced into each of the first and second receptacles. The presence of a nonparaffinophilic hydrophobic microorganism in the body specimen is determined by observing (i) a lack of microorganism growth on the paraffin coated material of the first support surface and (ii) a presence of microorganism growth on the hydrophobic material coating of the second support surface. The presence of the nonparaffinophilic hydrophobic microorganism can be further confirmed by performing a DNA extraction.

Abstract: A method for assaying a substance is provided in which an optical image is obtained from spots of light emitted from a chemiluminescent material capable of undergoing a luminescent reaction. The method comprises: (a) a step of distributing solid particles on the surface of a support, the solid particles having a diameter of not more than 100 .mu.

Abstract: A device and related method for performing one or more immunoassays to detect the presence of respective analytes in a sample. The device involves the use of a unitary bibulous material providing one or more flow paths having a common origin site and a plurality of respective reagent zones providing the reagents necessary for performing a visual readout, competitive immunoassay for the presence of the respective analyte.

Abstract: A method for evaluating the solubility capacity of free unbound estrogens in body fluids of animals is described.

Abstract: A drug abuse test kit has a transparent cup-like container for retaining a fluid sample to be tested and the open top end of the container is closed by an inner closure insert seated within the open end. There is a slit in the inner closure insert to receive a multiple drug test card having a plurality of immunoassay test strips thereon with visual endpoints to indicate presence or absence of a particular drug. The container is provided with an outer cover to close and seal the container when a sample therein is to be transported.

Abstract: A method of detecting heparin-induced antibodies to complete a diagnosis of heparin-induced thrombocytopenia (HITP) is disclosed. This method comprises the first step of attaching a glycosaminoglycan to a solid support, wherein the glycosaminoglycan is attached to the solid support only at the reducing end of the molecule (unidirectionally). Platelet factor 4 is then bound to the glycosaminoglycan forming a complex having an epitope recognizable by antibodies generated in an HITP immune response. Human blood plasma or serum from a patient suspected of having HITP is exposed to the complex and the complex is analyzed to determine if HITP-related antibodies are present. A device and kit used in performing the diagnostic assay are also disclosed.

Abstract: A test strip for use in determining the presence or concentration of an analyte in whole blood is disclosed. The test strip is a porous membrane having disposed thereon (a) a separating agent capable of separating from whole blood, red blood cells and a fluid component substantially free of red blood cells; (b) an indicating reagent system capable of indicating the presence or concentration of an analyte in the fluid component by producing a spectrophotometric change upon contact with the fluid component; and (c) an opaque filler capable of reducing spectrophotometric interference caused by the presence of the red blood cells. Also disclosed are methods of testing whole blood for the presence or concentration of an analyte using the test strip.

Abstract: Antibodies having binding affinity for free IGFBP-1, biological compositions including antibodies having binding affinity for free IGFBP-1, kits for detecting free IGFBP-1 using the antibodies, and cell lines for producing the antibodies are provided. Also provided are devices and methods for detecting free IGFBP-1 and a rupture in a fetal membrane based on the presence of amniotic fluid in a vaginal secretion, as indicated by the presence of free IGFBP-1 in the vaginal secretion. The antibodies that are provided may be characterized by their ability to selectively recognize those IGFBP-1 molecules which are free of IGF-1 and IGF-2, i.e., antibodies which have a binding affinity for free IGFBP-1 that is greater than a binding affinity of the antibody to bound IGFBP-1. These antibodies may also be characterized by their competition with IGF-1 and IGF-2 for binding to IGFBP-1.

Abstract: An analytical device for use in determining the presence of an analyte species of interest in a liquid state includes a chromatographic membrane support along which the liquid may travel, a plurality of first detectable particles associated with a sampling region of the device at which the liquid is to be applied, the particles being capable of being moved along the support by the liquid travel and having immobilised thereon a first binding agent capable of forming a first complex with the analyte species, a threshold region provided downstream of the sampling region in the direction of liquid travel, the threshold region being provided with a second binding agent which is capable of binding to non-complexed first binding agent on the particles, and which is present in an amount, such that a detectable number of the particles only pass the threshold region if the amount of analyte species in the sample is above a predetermined level, and a detection region downstream of the threshold region in the direction o

Abstract: A multi-test panel with several test strips containing a separate and different immunochromatographic system, each strip being housed in a separate structure so that the structures may be joined together and interchanged, depending upon what substances within a fluid sample are being detected.

Abstract: A test device for detecting or determining an analyte in a test solution includes an absorbent material having contact, liposome lysing and electrochemical measurement portions. The contact portion is positioned for contact with and uptake of the test solution. The liposome lysing portion is segregated from the contact portion and has a liposome lysing agent bound thereto. The liposome lysing portion is further either positioned between the contact portion and the electrochemical measurement portion, or partially or completely coincides with the electrochemical measurement portion. The electrochemical measurement portion comprises a first conductor comprising a plurality of fingers disposed on the absorbent material, and a second conductor similarly comprising a plurality of fingers disposed on the absorbent material, where the fingers of the first and second conductors are interdigitated to form an array.

Abstract: The present invention relates to a method and kit for carrying out a qualitative or semi-quantitative assay. The invention uses a multi-layer device including an an uppermost cover layer of a water-impermeable material having a hole therein with a diameter of approximately 1-5 mm, an intermediate insoluble porous support layer having a first substance bound thereon in a reaction zone, the hole exposing at least a part of the reaction zone, and a layer of a hydrophilic material in contact with and positioned on the side of the insoluble porous support layer opposite the side with the cover layer. The device permits transverse, but not substantial radial, diffusion of liquid through the reaction zone. Approximately 1-50 .mu.l of a test sample and a second substance are applied to the reaction zone through the hole. A colloidal gold label is attached to the second substance.

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: An assay device for detection or determination of an analyte in a sample uses either removably attachable components or hinged panels to provide greater flexibility and reduce manufacturing and storage costs. In one embodiment of the device, the device comprises: (1) a first opposable component including:(a) a first panel; (b) a second panel mounted on the first panel generally parallel to the first panel with space between the first and second panel, the second panel having an opening forming a first receptacle for a sample collection device; and (c) a second receptacle for a test strip formed by the first panel and the second panel; and (2) a second opposable component hingedly attached to the first opposable component. In this device, the first and second opposable components can be brought into operable contact so that fluid is expressed from the sample collection device and applied to the test strip for detection or determination of an analyte by a test performed on the test strip.

Abstract: A method and device for detecting the presence, absence or amount of an analyte in a whole blood sample is disclosed. The device comprises four zones, a sample receiving zone, a labeling zone, a capture zone and an absorbent zone. The sample receiving zone contains an irreversibly immobilized reagent that allows for removal of substantially all red blood cells from the whole blood sample. Flow through the device is via capillary migration and all of the dissolved or dispersed components in the sample flow at substantially equal rates and with relatively unimpaired flow through the device. The method involves the use of the device for detection of analyte in a whole blood sample.

Abstract: This invention provides a methodology for controlled biofilm formation in accordance with a monitored protocol. In a typical embodiment, a natural biofilm inoculum is used to form a simulated natural biofilm on retrievable slides in an annular reactor. The monitored protocol in the annular reactor subjects the bacterial consortia of the simulated natural biofilm to simulated environmental conditions. The invention simulated natural biofilm on a slide surface has utility for the testing of formulated product activity for inhibition or removal of the simulated natural biofilm, thereby providing a reliable indicator of the relative activity of the products under natural environmental conditions.

Abstract: The present invention relates to a dry immunoassay analytical element for assaying a ligand, comprising a support bearing: (a) a label zone comprising an enzyme labeled ligand or an enzyme labeled receptor; (b) a spreading zone; (c) a receptor zone comprising a fixed concentration of an immobilized receptor for the ligand; and (d) a gravure zone comprising a diaryl telluride. A prefered embodiment of the present invention further comprises a vanadyl salt. The present invention further relates to a method for performing an assay using an element as described above.

Abstract: A method and apparatus for evaluating estrogen dependent physiological conditions includes a substrate having an anthocyanin pigment applied thereto. The pigment yields a color response indicative of how the body fluid responds to changes in its capacity to absorb free estrogens. The pigment is contacted by the body fluid sample, and the response thereto is connected through color response or optical density measurements to predetermined physiological conditions.