Abstract: A chromatography assay device and method for use with whole blood samples utilizing a red blood cell separating agent to aggregate red blood cells and permit plasma or serum to flow by capillary action and a neutralizing agent to neutralize any effects the red blood cell separating agent may have on the device and method.

Abstract: Disclosed is a device and method of use for detecting polyvalent analytes such as antibody to the AIDS virus, utilizing an inverse sandwich method. The test device comprises a first substance having an epitope, bound to a label and capable of moving within the test device. The test device further comprises a second substance immobilized to the test device and spatially separated from the first substance. The second substance has an epitope substantially similar to the epitope of the first substance. Upon application to the test device, the polyvalent analyte binds to the first substance and moves within the test device to the location of the second substance with both polyvalent analyte and first substance are immobilized at location of the second substance. Polyvalent analyte is detected by the presence of the label at the location of the second substance. Also disclosed is a control substance for use with the device that can be used to determine completion of the test and viability of the device.

Abstract: A pretreatment method for assaying a substance which comprises mixing a biological specimen with at least one pretreating agent selected from among surfactants and alkali agents, thus releasing binding proteins in the biological specimen from the substance to be assayed and, at the same time, inactivating the proteins by irreversible denaturation to thereby eliminate the effects of the binding proteins coexisting in the biological specimen.

Abstract: The invention concerns a home kit and a method for detection of the presence of a fecal parasite in a stool.

Abstract: A particle-enhanced assay for determining an analyte in a test sample in which an additive for reducing non-specific particle aggregation is added in an amount to substantially reduce non-specific aggregation.

Abstract: A method for performing screening of one or more cell groups of interest obscured by a cell population such as one or more subsets of interest of a WBC population utilizing at least one light sensing parameter. The cell group of interest is enumerated by utilizing microspheres having monoclonal antibodies bound thereto to modify the sensed characteristics of specified cells to differentiate the cell group of interest from the obscuring cell population.

Abstract: In qualitative or quantitative assays which employ a test device comprising a test strip pretreated for detection of a specified target analyte dissolved in a liquid medium, the presence of solid, semisolid and/or colloidal materials in the liquid medium may interfere with the assay results. The present invention involves collecting the sample from a flowing or quiescent pool of liquid also containing solid, semisolid or colloidal material with a swab comprised of a handle and a mass of fibrous material or foamed, open cell material which, when immersed in and thoroughly wetted by the liquid, entraps solid, semisolid and/or colloidal material and delivers only the liquid to the sample receiving zone of the test strip.

Abstract: The present invention is drawn to an immunoassay capable of the rapid detection of a variety of test substances that may be present in a test sample. One feature of the invention is that extraction or isolation of the test substance occurs simultaneously with the formation of the primary antigen-test substance complex. The primary antigen-test substance complex is then captured in a solid phase format having a plurality of interstitial spaces which facilitate rapid and efficient detection. The immunoassay of the present invention works over a wide range of environmental conditions and is simple enough to be used in the absence of laboratory facilities.

Abstract: A lateral flow testing device is provided for testing a biological fluid for the presence of methamphetamines. The device includes a substrate element such as a nitrocellulose strip, including an antibody zone and an immobilized drug conjugate zone for detecting presence of methamphetamines, and an on-board chemical reactant for preventing undesirable cross-reactivity to ephedrine and/or pseudoephedrine that may be present in the biological fluid being tested. Preferably, the on-board chemical reactant is sodium periodate. Methods for preparing test devices are provided including the step of striping a substrate sheet with a solution containing sodium periodate during manufacture of methamphetamine lateral flow test strips.

Abstract: The invention concerns a method for the determination of antigen-specific antibodies of the immunoglobulin M class in the presence of immunoglobulins of the G class and/or rheumatoid factors in body fluids by incubation with at least two different receptors R1 and R2 and optionally additional receptors wherein an essential component of R2 is a binding partner in a polymeric form and interference by IgG antibodies of the same antigen specificity is reduced by binding partners in a monomeric form; a reagent for determining an antigen-specific antibody of the immunoglobulin M class, as well as the use of binding partners in a monomeric form to reduce interference by IgG antibodies in the determination of antigen-specific IgM antibodies.

Abstract: The invention concerns a method for the determination of an analyte in which rheumatoid factors or rheumatoid-factor-like substances are added as an interference reducing reagent to reduce of avoid a hook effect. The invention in addition concerns suitable reagent kits for carrying out the method.

Abstract: Methods and apparatus for qualitatively or quantitatively determining one or more analytes in matrices such as foods, biological fluids, etc. An embodiment for determination of a single analyte comprises a sample receiving vessel, a first membrane and a reagent-containing well. The prepared sample passes through the first membrane whereby extraneous matter is removed, and a filtrate enters the reagent-containing well to provide a filtrate-reagent admixture from which the analyte may be determined. An embodiment for determination for multiple analytes includes one or more additional membranes in series with the first membrane, each such additional membrane being operative to capture one or more analytes. Each of the additional analytes may then be eluted from the membrane upon which it has been captured, into a separate reagent-containing well to provide eluant-reagent admixture from which each desired analyte may be determined. Formulations for preparation additives are also included.

Abstract: A homogeneous assay for determining the fumonisin content in grains uses the technique of fluorescence polarization. A grain extract is prepared by shaking a crushed grain sample with a solvent. A mixture is prepared by combining the grain extract with a tracer and with monoclonal antibodies specific to fumonisin. The tracer is able to bind to the monoclonal antibodies to produce a detectable change in fluorescence polarization. The tracer is prepared by conjugating fumonisin to a suitable fluorophore. The fluorescence polarization of the mixture is measured. The fumonisin concentration of the mixture may be calculated using a standard curve obtained by measuring the fluorescence polarization of a series of fumonisin solutions of known concentration.

Abstract: The present invention is an improvement to the method of determining the concentration of an analyte in body fluid using at least two immunoreactants which specifically bind with separate epitopes of the analyte one of which immunoreactant is immobilized on a solid support and the other is in the form of a polymer or oligomer of the immunoreactant and an enzyme. The improvement involves introducing to the assay system a polymeric conjugate of the enzyme and a water soluble protein other than the enzyme or a non-proteinaceous natural, synthetic or semi-synthetic polymer or oligomer in sufficient amount to reduce bias in the assay due to incorrect recovery of the analyte.

Abstract: The present disclosure relates to a method for determining cholesterol in low density lipoprotein comprising the steps of (a) measuring total cholesterol level in a sample containing at least high density lipoprotein, low density lipoprotein, very low density lipoprotein and chylomicron, and (b) measuring cholesterol levels in the high density lipoprotein, very low density lipoprotein and chylomicron in the sample, wherein the cholesterol level in the low density lipoprotein is determined by subtracting a value obtained in step (b) from a value obtained in step (a). The present invention enables concurrent determination of cholesterol level in low density lipoprotein and total cholesterol level, facilitating acquisition of two types of biological information at a time.

Abstract: The invention relates to a method of evaluating the immunological status of a subject comprising the steps of 1) determining the content of an antibody in a liquid sample from the subject using an immunoassay, wherein the reaction between the antibody of the sample and a ligand in the form of an antigen, an antibody or a hapten, the ligand being directed to the Fab region of the sample antibody, is carried out in the presence of other constituents of the sample to obtain a measurement 1, 2) determining the content of an antibody in the liquid sample using an immunoassay, wherein the reaction between the antibody of the sample and a ligand in the form of an antigen, an antibody or a hapten, the ligand being directed to the Fab region of the sample antibody, is carried out in the absence of other constituents of the sample to obtain a measurement 2, and 3) interrelating measurements 1 and 2 to express the interference and using the interference as a parameter for evaluating the immunological status of the subje

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: The invention concerns methods for the detection of an analyte in a sample by chemiluminescence or electrochemiluminescence using derivatized test reagents. In addition new reagents and reagent kits for chemiluminescence and electrochemiluminescence detection methods are disclosed.

Abstract: A hybridoma cell line has been produced for secreting a monoclonal antibody that binds ractopamine and is effective to detect ractopamine levels of about 1 ng/mL or lower. This monoclonal antibody may be used for the detection and quantitative determination of trace amounts of ractopamine in samples, especially in animal tissue, body fluids and feed material.

Abstract: The use of calcium salts, magnesium salts or combination thereof in immunochemical methods for the determination of an analyte in a sample. These salts increase the specificity of such determinations, in particular, the background signal being reduced by addition of these salts in solid phase immunochemical methods.

Abstract: There is described a method for the chemical modification of antibodies and/or antigens in order to minimise sample interference in immunoassays, an immunoassay method in which chemically modified antibodies and/or antigens are employed, the use of chemically modified antibodies and/or antigens in an immunoassay and a kit for assaying biological specimens which comprises the chemically modified antibodies and/or antigens.

Abstract: Tumor cells, particularly carcinoma cells, are separated from peripheral blood by magnetic sorting. The tumor cells are magnetically labeled with antibodies directed to tissue specific antigens, preferably cytoplasmic proteins. Labeling for cytoplasmic antigens is accomplished first permeabilizing, then fixing the cells. The cells are separated on a magnetic matrix. The number of tumor cells in the enriched fraction is used to calculate the number of tumor cells present in a patient hematopoietic sample.

Abstract: A method of measuring the amount of cyclosporin in a sample suspected of containing cyclosporin is disclosed. A method of inactivating interfering cross-reactive material in an assay for measuring the amount of cyclosporin in a sample suspected of containing cyclosporin is also disclosed. Compositions wherein cyclosporin is conjugated to an immunogenic carrier or a label, optionally through a linking group, at an alanine nitrogen atom of the cyclic backbone of cyclosporin are also disclosed. Compositions wherein atiocyclosporin is conjugated, optionally through a linking group, to an immunogenic carrier or a label are also disclosed. Where cyclosporin is conjugated to an immunogenic carrier, the conjugates may be used as immunogens for the preparation of antibodies which are capable of recognizing cyclosporin.

Abstract: A method of determining the concentration of a sample antigen in the presence of an interferant by (1) running two immunoassays on the sample: one assay where the interferant influences the binding of both the sample antigen and a labeled antigen and a second assay where the interferant influences the binding of the sample antigen but not the labeled antigen; (2) obtaining a plot of the possible sample antigen concentrations versus the possible interferant concentrations corresponding to the readout for the sample for each of the two immunoassays; and (3) determining the sample antigen concentration and the interferant concentration which correspond to the point that appears on both of the immunoassay plots.

Abstract: One aspect of the present invention relates to a method for releasing a ligand from a complex thereof. The method comprises contacting a medium suspected of containing such complex with an effective amount of a compound effective in releasing the ligand. Another aspect of the present invention is an improvement in a method for the determination of an analyte that is a member of a specific binding pair in a sample suspected of containing such analyte. The method comprises the steps of (a) providing in an assay medium the sample and a binding partner for the analyte and (b) detecting the binding of the binding partner to the analyte. The improvement comprises including in the assay medium a compound of the invention in an amount sufficient to enhance the accuracy of the determination. The invention has particular application to a method for releasing mycophenolic acid from a complex thereof.

Abstract: The presence of endotoxin in the outer membrane of cell wall of a Gram-negative bacteria is used to determine bacterial contamination in a biological product. The amount of endotoxin present in a biological product is accurately measured without influence of a limulus reaction-activating substance which causes a false-positive reaction, by a method including the steps of: inactivating the limulus reaction-activating substance, if any, in the biological product, by exposing the biological product to a surfactant at a temperature ranging from the surfactant's freezing point to 50° C.; and measuring the amount of endotoxin present in the biological product, using a limulus reagent.

Abstract: A sample is prepared from blood in a manner which makes it possible to further analyze proteins in the sample, e.g. to detect prions in the sample. Blood is extracted, allowed to clot and subjected to separation processing (e.g. centrifugation) to obtain serum. The serum is treated with a complexing agent which agent binds prions in the sample forming an agent/protein complex which makes it possible to concentrate the complex. Concentration of the complex results in a sample which can be successfully analyzed, e.g. assayed using a range of different types of assay methodologies for detecting prions.

Abstract: There is provided a method and kit for measuring the amount of an objective constituent contained in a specific lipoprotein in a biological sample such as serum and plasma, specifically for measuring the amount of cholesterol contained in high density lipoprotein, which can be applicable to clinical tests.

Abstract: One aspect of the present invention relates to assays for the detection of mycophenolic acid. The method comprises including in an assay medium suspected of containing mycophenolic acid a releasing agent for releasing mycophenolic acid from a complex with endogenous proteins. Another aspect of the present invention is an improvement in a method for the determination of mycophenolic acid in a sample suspected of containing such analyte. The method comprises the steps of (a) providing in combination in an assay medium the sample and a binding partner for the analyte and (b) detecting the binding of the binding partner to the analyte. The improvement comprises including in the assay medium a releasing agent for releasing mycophenolic acid from a complex with endogenous proteins. The present invention also provides assay reagents as well as packaged kits useful for performing the methods of the invention.

Abstract: A process for determining glycosaminoglycans in antithrombin III (ATIII)-containing solutions by increasing the ionic strength of the AT III-containing solution until the interaction between AT III and glycosaminoglycans is prevented, removing the AT III which has been released from the glycosaminoglycans from the solution, and desalting and determining the glycosaminoglycan which has remained in the solution.

Abstract: This invention relates to an improvement in a method for detecting labeled molecules and especially biotinylated molecules and particularly relates to a method for reducing background signal problems in such detection methods.

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: In a fluorescence polarization assay for determining the amount of a target analyte in a test sample, wherein the amount of analyte is related to the amount of fluorescence emitted from the analyte-containing reagent medium, the improvement comprising contacting the analyte-containing reagent medium with of at least one compound from the group consisting of 1,10-phenanthroline, 8-hydroxy-7-iodo-5-quinoline, naphthalene-1-sulfonic acid, salts thereof, and any combination thereof.

Abstract: The present invention relates to methods for substantially reducing adsorption of at least one positively charged molecule to a negatively charged surface upon contact therebetween, the method comprising combining the positively charged molecule with at least one blocking agent in an amount sufficient to substantially reduce the adsorption of the positively charged molecule to the negatively charged surface.

Abstract: The invention provides a new method for antiglobulin testing from serum of a potential blood transfusion recipient in which warm autoantibodies are removed from serum so as to allow identification of alloantibodies present. The method involves contacting serum from a patient with one or more ligands that bind warm autoantibodies but do not bind alloantibodies, separating the non-bound serum components from the bound warm autoantibodies, and using the warm autoantibody-depleted serum in antiglobulin testing. Suitable ligands include phospholipids, the polar head groups of phosphoglycerides, and naturally occurring and synthetic analogues of these molecules.

Abstract: A method is provided, in one embodiment, for the determination of an analyte in a biological fluid sample in the presence of a substance interfering with an assay for the analyte. This embodiment is implemented by using antibodies to cause the selective immunoreaction of at least one of the analyte or the interfering substance and then conducting an assay for the analyte in at least one of the immunoreactants or the non-reactants. Another embodiment provides a disposable reaction device to implement the method. The invention is applicable to the detection of a wide variety of analytes, including cholesterol in a targeted lipoprotein class in the presence of cholesterol in another class; to targeted isozymes of enzymes such as creatine kinase, lactate dehydrogenase, amylase, and alkaline or acid phosphatases in the presence of other isozymes; as well as to targeted immunoglobulins in the presence of non-targeted immunoglobulins.

Abstract: The present invention relates to novel methods and devices for detecting non-complexed prostate specific antigen (free PSA), which is used in conjunction with total PSA tests to identify patients having either benign prostatic diseases (BPD), such as benign prostatic hyperplasia, prostatitis, or glandular atrophy or prostatic adenocarcinoma (CAP). In a biological sample, one can find not only free PSA, but also prsotate specific antigen (PSA) which has formed a complex with .alpha.1-antichymotrypsin (ACT). The present invention removes complexed PSA (PSA-ACT) from a fluid sample, thereby removing any possible interference due to binding of complexed PSA to an allegedly free PSA specific antibody in an immunoassay for free PSA.

Abstract: An improved method for detecting even low titer HLA antibodies in proposed organ transplant recipients employs flow cytometry crossmatching (FCXM) on pronase-treated B-cells and T-cells of the donor. Two-color FCXM is preferably employed. The peripheral blood lymphocytes, after pronase digestion, are maintained under conditions to suppress Fcy R receptor regeneration, combined with sera of the proposed transplant recipient, and tested against control sera, using fluorescent reporting complexing agents. Use of pronase digested lymphocytes permits the assay to distinguish between normal or irrelevant IgG B cell binding and immunologically important HLA antibody binding.

Abstract: The invention addresses new photo-activatable biotin derivatives having the formula I ##STR1## wherein R=?(CH.sub.2).sub.n --O.sub.m !.sub.q --?(CH.sub.2).sub.r --O.sub.s !.sub.t --(CH.sub.2).sub.pwith n,r=2,3; m,s=0,1; q+t=1-4; p=1-4,wherein the sum of all CH.sub.2 groups does not exceed 10and wherein R1 as a single or multiple substituent is hydrogen, C.sub.1 -C.sub.5 alkyl, NH.sub.2, COOH, F, Cl, or Br.and their preparation, their use to inactivate streptavidin, the use of the inactivated streptavidin to reduce interference in immunoassays.

Abstract: An elcctrobiochemical system for the determination of the presence and optionally concentration of an analyte in a liquid medium, the system comprising an electrode having immobilized thereon a member of a recognition pair, the other member of said pair being said analyte, the presence of said analyte in the medium resulting in formation of a pair complex, being a complex between said immobilized member and said analyte; the system further comprising redox molecules capable of changing their redox state by accepting electrons from or donating electrons to the electrode; the formation of the pair complex on the electrode bringing a change in the electrical response of the system, whereby the presence and optionally the concentration of said analyte in the medium can be determined.

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: For the qualitative or/and quantitative detection of a substance to be determined in a test sample with the aid of an immunoassay or nucleic acid hybridization assay the following components are used:a) a capture reagent which enables a specific detection of the substance to be determined by means of two different binding sites 1) if desired together with further test components and 2) is bound or is capable of binding to an active solid phase via a specific binding pair one partner of which is linked to the capture reagent and the second partner of which is coupled to an active solid phaseb) an active solid phase andc) an inactive solid phase which substantially corresponds to the active solid phase but to which the capture reagent cannot bind,wherein the test sample is either firstly brought into contact with the inactive solid phase alone and only later with the active solid phase, or is simultaneously brought into contact with the active and inactive solid phase during which the capture reagent and if des

Abstract: Disclosed is a method for pretreating heat stable proteins derived from a rendered animal material prior to performing an assay for their presence comprising (a) preparing a protein containing extract of the material, (b) removing substantially all or part of the gelatin from the extract and (c) concentrating the remaining protein such that it tests positive for protein by immunoassay at a dilution of greater than 1 in 6,000.

Abstract: Disclosed is an improved method for the detection of an analyte in a fluid test sample using a strip of a negatively charged matrix material having a zone containing mobile, labeled binding partner for the analyte and a separate zone for capturing the labeled binding partner as it is carried through this zone by the fluid test sample. The improvement involves combining the fluid test sample with a polyalkoxylated amine surfactant to control non-specific binding of the labeled binding partner to the negatively charged matrix material.

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: A deepithelialized skin cell diffusion system which can be used to select topical gel and cream formulations containing human other wound healing promoters such as plasma fibronectin. The formulations provide slow release and increased contact time of fibronectin or other wound healing promoters to the wound site leading to its effective absorption.

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 kit of two liquid reagent components for determining the fructosamine content of a blood sample measured by color change, and methods of determining fructosamine content of a blood sample using these two liquid reagents are disclosed.

Abstract: The invention concerns interference-eliminating agents for avoiding unspecific interactions in immunoassays in which avidin or streptavidin or a derivative thereof are used as the interference-eliminating agents.