Abstract: The present invention provides cross-linked protein compositions consisting of two or more units of a target-specific protein joined by binding sulfhydryl groups on the target-specific protein units to a sulfhydryl-selective cross-linking agent and a method of making the compositions. These cross-linked protein compositions combine an increase in binding affinity due to the presence of multiple identical binding sites and stability to reduction conditions.

Abstract: A trifunctional conjugate is provided having three chemical moieties, attached through a spacer moiety. At least two of the chemical moieties are relatively small molecules, usually less than about 7,000 Daltons in size. The spacer moiety is selected to impart certain steric properties to the conjugate. In one embodiment, the binding of a macromolecular specific binding partner to one of the chemical mouths sterically inhibits the binding of a different macromolecule to another chemical moiety. In another embodiment, the binding of a first chemical moiety to a macromolecule restricts the subsequent binding of a second chemical moiety to a proximate location on the same macromolecule.

Abstract: A quantitative determination of a substance is performed in a homogeneous system based on a change in enzyme activity; differences between the activity of a free enzyme and that of an enzyme bound by an aggregation or chemical bonding are observed. A peroxidase-labeled antibody and antigen system is one of of the typical example. Since the reaction is effected in a homogeneous system, the amount of antigen can be easily measured by the difference of enzyme activity.

Abstract: There is disclosed a process for minimally derivatizing a targeting protein with a radionuclide such that the predominant species of derivatized targeting protein contains one radionuclide group as a single radiolabeled ligand, and whereby the binding characteristics of the targeting protein are minimally affected. There is further disclosed ligands that can chelate a metal radionuclide or bind a halogen radionuclide while providing a means for separating radiolabeled ligand from unradiolabeled ligand.

Abstract: A method for immunoassay for an antigen involves the following steps: reacting a sample possibly containing an antigen to be determined, a definite amount of a conjugate of the antigen and a charged substance and a definite amount of labeled antibody specific for antigen; allowing the reaction products to electrophoretically migrate towards a carrier bearing an attached antibody specific for the charged substance, so that when the reaction products contact the carrier any reaction product of labeled antibody and antigen passes through the carrier and any reaction product of the labeled antibody and conjugate binds to the carrier attached antibody specific for the charged substance; determining the amount of labeled antibody thereby bound to the carrier and relating the determined amount of labeled antibody to the amount of antigen in the sample.

Abstract: A method is disclosed for conducting an assay for an analyte. The method comprises causing a specific binding pair member in a first aqueous medium to become bound to a first bibulous member by contacting a portion of the first bibulous member with the medium. The first bibulous member is in liquid receiving relationship with an absorbent member. The contacting is carried out under conditions wherein the first medium traverses the first bibulous member and at least a portion of the absorbent member by capillary action. The method further comprises causing the first bibulous member to come into liquid receiving relationship with a second bibulous member. A reagent in a second aqueous medium is absorbed by and preferably becomes a non-diffusively bound to the second bibulous member in relation to the presence of analyte in the first medium.

Abstract: The invention relates to an immunometric assay for a multivalent antigen in a sample which comprises forming a complex of the antigen together with multiple immobilized monoclonal antibodies against different epitopes of the antigen and with a detectably labeled soluble monoclonal antibody which is identical to one of the multiple immobilized antibodies. The labeled antibody associated with the complex is separated from the remaining soluble antibody and the detectably labeled antibody associated with the complex or unassociated with the complex is detected. Any one of the multiple immobilized monoclonal antibodies shows, by itself, substantially less binding towards the antigen in the immunometric assay, when used with itself or another monocolonal antibody in soluble labeled form, than when used with the multiple immobilized antibodies in combination.

Abstract: Assay for determing the nucleic acid sequence in a region of a nucleic acid test substance having a known normal sequence and a known possible mutation at at least one target nucleotide position. Oligonucleotide probes are selected to anneal to immediately adjacent segments of a substantially complementary test DNA or RNA molecule. The target probe has an end region wherein one of the end region nucleotides is complementary to the normal or abnormal nucleotide at the corresponding target nucleotide position. A linking agent is added under conditions such that when the target nucleotide is correctly base paired, the probes are covalently joined and if not correctly base paired, the probes are incapable of being covalently joined under such conditions. The presence or absence of linking is detected as an indication of the sequence of the target nucleotide.

Abstract: The present invention provides a process for the determination of a bindable analyte according to the principle of heterogeneous immunoassay by incubation of a sample solution which contains the analyte with a labelled first receptor specifically bindable with the analyte and present in dissolved phase and a second receptor present in a solid phase which does not cross-react with the first receptor and can fix a complex which contains the analyte and first receptor, separation of the phases after incubation and quantitative measurement of the labelling bound to the solid phase, wherein there is determined the back dissociation velocity of the labelling bound to the solid phase into the dissolved phase and the quotients of the back dissociation velocity and measurement value are used as a measure for the correctness of the test result of the first measurement.

Abstract: The present invention provides a process for the determination of an antibody in human body fluids according to the immunoassay principle in which a sample containing the antibody to be determined is incubated with at least two different receptors R.sub.1 and R.sub.2, of which one receptor R.sub.1 carries an antigenic determinant specific for the antibody to be determined and one receptor R.sub.2 carries a label to form bound and unbound label, the part which contains the bound label is separated from the part which contains the unbound label and the label is measured in one of the two parts, wherein, for the control, instead of the sample, there is used a standard solution which contains a conjugate of a bindable non-human antibody or a Fab or F(ab').sub.2 fragment thereof which non-human component binds with a receptor R.sub.s which also binds to the antibody to be determined, and a human immunoglobulin or the Fc part thereof.

Abstract: Proteinaceous, antigenic factor derived from a group C Streptococcus which is receptor for the Fc region of IgG, a method for its preparation and immunoassay and antigen detection methods employing the receptor.

Abstract: New immunosorbent enzyme assays are provided employing antibiotic keying agents for binding a molecular species to be detected to a test surface followed by binding of an antibody specific for the species and detection of the antibody-species binding. In accordance with preferred embodiments, soluble peptidoglycan is assayed in a fluid binding it to a test surface with vancomycin, reacting the bound material with a peptidoglycan specific antibody, and measuring the extent of the antibody reaction. Assessment of bodily fluids and fermenation broths for the presence of certain kinds of antibiotics is one object of this invention. Assessment of sera for the presence of antibodies that have specificity for soluble peptidoglycans is another object of this invention. Assessment of bodily states in mammals is another object of the invention.

Abstract: For the determination of a reaction partner of an immunological reaction according to the principle of immunoassay, the reaction partner to be determined is brought into contact with a marked specific receptor R.sub.1 and at least 1 unmarked receptor R.sub.2, one of the unmarked receptors R.sub.2 being bonded on a solid phase by a binding-capable substance R.sub.3. In order to determine the sample blank value, the unmarked receptor R.sub.2, which is bonded by the receptor fixed on the solid phase, is then replaced by another unmarked receptor R'.sub.2 which does not react with the reaction partner of R.sub.2 to be determined.

Abstract: Antibody coated gold sol particles and antibody coated solid phase particles dispersed in an aqueous system react immunologically as a function of the presence of an analyte in a sample to be analyzed to produce a collectible, solid phase, gold-containing composite. The composite is collected on a filter or at the bottom of a test tube by centrifugation or gravitation and the analyte in the sample is determined or detected by direct visual examination of the collected solid phase composite which has a pink or red or purplish coloration as a result of the gold contained thereby. The materials required for conducting the assay comprise coated gold particles, coated solid phase particles and a collector element such as a filter. The collected, solid phase, metal-containing composite, which may be directly visually examined to determine or detect the gold therein and thus the analyte in the sample, is stable and remains available for confirmation of test results at a later time.

Abstract: A simultaneous sandwich immunoassay employing high-affinity monoclonal antibodies is disclosed. This simultaneous sandwich assembly has surprising sensitivity compared to forward and reverse sandwich assays for the detection of multi-determinant antigens such as hepatitis B surface antigen.

Abstract: A device is provided for determining the presence of an antigen which comprises a trapping zone, which contains material capable of capturing free flowing enzyme linked antibodies, but not antibodies bound to a transport particle which flows freely through the trapping zone into the substrate zone, and a substrate zone which contains material capable of reacting with enzyme-linked antibodies to produce a reaction which indicates the presence of antibodies. A method of determining the presence of an antigen is provided wherein a sample is mixed with two classes of antibodies which are specific for the antigen being tested for, but which react with different antigen domains, wherein the mixture consists of class one antibodies bound to a transport particle which flows freely through the trapping zone and class two enzyme-linked antibodies which are incapable, unless bound to the transport particles, of flowing freely through the trapping zone.

Abstract: A highly sensitive and specific monoclonal-immuno-radiometric assay (M-IRMA) for hCG, using monoclonal antibodies (Mabs) directed against a 37-amino acid synthetic polypeptide analogous to the carboxyl terminus (CTP) of beta-hCG. Accordingly, in one embodiment, a method is described for the determination of human chorionic gonadotrThe present invention was made utilizing funds of the United States Government. The U.S. government is therefore granted a royalty-free, non-exclusive, world wide, paid-up license in this invention.

Abstract: An antibody specific to trifluralin can be produced by first substituting a soluble, straight chain amino acid for a propyl group of .alpha.,.alpha., .alpha.-trifluoro-2,6-dinitro-N-N-dipropyl-p-toluidine. The trifluoro group at the 4 position, the nitro group at the 2 position and the other nitro group at the 6 position are left exposed. Thereafter, the resulting substitution product is conjugated, at the site of the substituted amino acid group, with a lysine-rich protein. The resulting compound is then used as an antigen to evoke an immune response in a host animal or antibody producing cell line. The antibody produced against the antigen is then harvested and used in an assay such as a radioimmunoassay or enzyme linked immunosorbant assay (ELISA) to determine the presence and concentrations of trifluralin in agriculturally significant substances such as plant materials, soil and water or to otherwise test for trifluralin contamination of water, food and air.

Abstract: A method for assaying for a ligand analyte which is a member of a specific binding pair ("sbp member") consisting of ligand and its complementary receptor is disclosed. The ligand analyte has a binding site in common with an interfering substance present in a sample suspected of containing the analyte. The interfering substance has at least two binding sites. The method comprises combining in an assay medium without intervening separation (1) the sample, (2) a blocking receptor which does not bind to the ligand and does bind to the interfering substance, thereby blocking the binding of a common receptor to the interfering substance, and (3) a common receptor which binds to the common binding site. Any additional members of a signal producing system capable of producing a detectable signal in relation to the amount of analyte in the sample are added to the assay medium. Next, the assay medium is examined for the presence of a detectable signal.

Abstract: A process for the detection and assay of a biological substance by erythroadsorption by immobilizing a substance having a binding affinity for the biological substance to be assayed; incubating the immobilized substance with a liquid medium containing the biological substance to be assayed, forming a fixed substance; incubating the fixed substance with a coupling product comprising a specific ligand and a second ligand which binds with erythrocytes; adding erythrocytes; and determining the amount of erythrocytes bound to the coupling product. The determination of the amount of bound erythrocytes can be made visually with the naked eye or determined by lysis of the erythrocytes bound to the coupling product and quantitatively measuring the released hemoglobin. The specific ligand can be an antibody or an antigen and the second ligand capable of coupling erythrocytes can, for example, be red blood cell antibodies.

Abstract: A novel method for the determination of protecting anti-HBV immunoglobulins is based on the use of two different HBsAg reagents: one insolubilized and having the antigenic type AX and one labelled and having the antigenic type AY, wherein A represents the epitope or epitopes which are common to all HBsAg serotyes, wherein X and Y both represent combinations of the epitopes which are not common to all HBsAg serotypes, and where the combinations X and Y have no epitopes in common.

Abstract: At least two antigens in a sample may be detected using an immunometric dual sandwich assay containing an effective amount of at least one monoclonal antibody against each antigen, which antibodies are separately conjugated with the same or different signal moieties as labels, and an effective amount of at least one unlabeled monoclonal antibody against each antigen which unlabeled antibodies are immobilized on a single support. Preferably the antibodies are all products of different cell lines and the antigens are prostatic acid phosphatase and prostate antigen.

Abstract: A method of immunoassay of an antigen in a liquid sample wherein a complex is formed between antigen contained in the said sample and two or more antibody reagents, and the said complex is bound to a solid support by non-covalent bonding as defined herein; and the amount of complex becoming bound to the support is determined; the process employing at least one monoclonal antibody reagent. Labelling methods including radio-active, fluorimetric and enzyme labelling may be used to effect determination of the binding of the complex to the solid support. The solid support may take the form of particles, beads, wall-coatings on the reaction vessel or an insert of large surface area. The method is particularly applicable to the assay of TSH, CEA, HCG, alphafeto protein, immunoglobulins, viruses, allergens, bacteria, toxins, drugs and vitamins. Use of monoclonal reagents improves the specificity of the process, and also decreases non-specific binding.

Abstract: Binding of a particular protein by an antibody reagent involving denaturation of the protein and use of an antibody reagent specific for binding a linear peptide epitope therein. Denaturation by chemical or physical means effectively exposes or enhances the exposure of the linear peptide epitope for binding by the antibody reagent which is preferably raised against a synthetic peptide immunogen. The technique is particularly useful in performing immunoassays for protein analytes, such as a glycosylated protein, in aqueous test samples.

Abstract: An enhanced agglutination assay method for determination of a multivalent analyte is disclosed. Analyte is added to agglutinatable particles coated with anti-analyte molecules to produce particle agglutination. The extent of agglutination is enhanced by mixing the particles and analyte with an analyte-binding reagent composed of lipid bodies. The reagent bodies act by promoting multiple analyte bridge connections between individual bridged particles and a reagent body. Also disclosed is a kit containing such particles and reagent.

Abstract: An immunoassay by which a plurality of kinds of antigens or antibodies in one test sample may be simultaneously quantified. Each of a plurality of kinds of microcapsules is first provided for each kind of a plurality of antigens or antibodies to be quantified such that the microcapsules bind an antibody or antigen specific to one kind of the plurality of antigens or antibodies to be quantified. The microcapsules are formed of a membrane capable of being lysed by the complement activity, and each kind of microcapsules contains therein a substance that is quantifiable and does not interact with another quantifiable substance contained in other kinds of microcapsules. The plurality of kinds of microcapsules are mixed with a test sample and complement, and the quantifiable substances are released from the microcapsules upon lysis of the microcapsules by the complement activity. The quantifiable substances are then quantified.

Abstract: An agglutination assay reagent and method. The reagent is composed of liposomes predominantly in the 1 to 20 micron diameter size range. Each liposome has a surface array of laterally mobile ligand molecules, at a surface concentration adapted to produce reagent agglutination within about 5 minutes, when the reagent is incubated at room temperature with a multivalent ligand-binding analyte. A dye in the liposomes allows such agglutination to be visualized easily without magnification.

Abstract: A composition having a protein binding solid support onto which is bound a mixture of antigens and antibodies which are both bound to the solid support individually and are not present in the form of an immune complex.

Abstract: An immunoassay for assaying an antigenic substance (Ag) in a fluid. The immunoassay is the type which comprises contacting the fluid with at least one first entity selected from a group consisting of an antibody (Ab) to the Ag, a soluble, labeled antibody (L-Ab.sub.a) to the Ag, and an antibody (Ab.sub.b) to the Ag bound to a solid support (SC). The immunoassay is characterized in that the fluid is contacted with at least one additional entity selected from a group consisting of at least one different type of soluble, labeled antibody (L-Ab.sub.c) to the Ag, at least one different type of antibody (Ab.sub.d) bound to a solid carrier (SC.sub.1), and at least one different type of antibody (Ab.sub.e) to the Ag. The SC.sub.1 is selected from a group consisting of SC, at least one different solid carrier (SC.sub.2), and mixtures thereof (SC and SC.sub.2). Each type of L-Ab.sub.c, Ab.sub.d -SC.sub.1, and Ab.sub.e has a lower average affinity constant (K) for Ag than each respective K of L-Ab.sub.a, Ab.sub.

Abstract: The use of anti-idiotype antibodies as functional substitutes for antigens or haptens in immunoassays is disclosed.

Abstract: This invention relates to an antibody capable of both specifically detecting and quantifying minute quantities of the herbicide, atrazine, left in biological samples, such antibody having been made by the process of first substituting a soluble straight chain amino acid at the 4 or 6 position of 2-chloro-4(isopropylamino)-6-(ethylamino)-S-atrazine so as to leave the chlorine exposed at the 2 position along with one of the amino groups, then conjugating the resulting substitution product at the site of the amino acid group to a lysine-rich protein, using the mixed anhydride method in a strongly-basic aqueous solution, then inoculating a susceptible host with the antigen to evoke an immune response, and thereafter harvesting the antibody.

Abstract: The antigens procollagen peptide (type (III) and procollagen peptide col 1 (type III) can be determined together immunologically by either(a) reacting a specified amount in each case of labeled procollagen peptide (type III) or procollagen peptide col 1 (type III) and a highly specific antiserum containing antibodies having affinity for both the antigens mentioned together with a sample having an unknown content of procollagen peptide (type III) and/or procollagen peptide col 1 (type III), separating off the antigen-antibody complex formed and measuring the amount of labeling in the complex and/or in the supernatant, or(b) bringing a specified amount of the highly specific antiserum to reaction with a sample having an unknown content of procollagen peptide (type III) and/or procollagen peptide col 1 (type III), fixing the unreacted amount of the antibody to procollagen peptide (type III) or procollagen peptide col 1 (type III) bound to a support, and bringing to reaction with a labeled second antibody, and th

Abstract: In a method for immunochemical assay of human chorionic gonadotropin involving use of an antibody immobilized on a carrier, an antigen and an antibody to which a labeling agent has been attached, when the antibody supported on the carrier and the antibody coupled to a labeling agent are different antibodies which are not overlapping in antigen-determining site and one of said different antibodies is specifically reactive to human chorionic gonadotropin, a high reproducibility of the result of the immunochemical assay is obtained.

Abstract: Lipid vesicles, labelled with encapsulated reporter compositions and bound to antibodies comprise a new class of immunoreagent, useful in immunoassays for ligands.

Abstract: Antibodies having binding affinity for two desired antigens, hereinafter "recombinant monoclonal antibodies"; recombinant monoclonal antibodies produced by a quadroma cell or a trioma cell; and methods for producing recombinant monoclonal antibodies by means of a quadroma cell or a trioma cell, wherein a quadroma cell is the fusion product of a hybridoma cell which produces an antibody having specific binding affinity to one desired antigen and a hybridoma cell which produces an antibody having specific binding affinity for another desired antigen, and wherein a trioma cell is the fusion product of a hybridoma cell which produces an antibody having specific binding affinity to one desired antigen and a lymphocyte which produces an antibody having specific binding affinity to another desired antigen.

Abstract: Two-site immunometric assays for multideterminant antigens are described in which the antigen is reacted with an immobilized monoclonal antibody directed against one antigen determinant and a second monoclonal antibody that is directed against a distinct antigenic determinant and is of a different class or subclass than the immobilized monoclonal antibody. The second monoclonal antibody is labeled in direct versions of the assay and is reacted with a labeled antibody against it in indirect versions of the assay. The immobilizing medium and classes (subclasses) of the antibodies may be selected so as to reduce the likelihood of nonspecific binding enhance sensitivity and/or permit signal amplification.

Abstract: Methods of manufacturing and purifying metal chelate conjugated monoclonal antibodies are described. The chelated metal may be one which emits alpha, beta or gamma radiation, or positrons. Alternatively, the metal can be one which is fluorogenic or paramagnetic. The conjugates are suited for diagnostic and therapeutic uses.

Abstract: Therapeutic and diagnostic methods employing metal chelate conjugated monoclonal antibodies are described. Metals employed in therapeutic conjugated antibodies include alpha particle, beta particle or Auger electron emitting isotopes. Diagnostic methods may be either in vivo or in vitro. Chelated metals employed in diagnostic techniques may include, inter alia, gamma or positron emitting metals as well as fluorogenic or paramagnetic metals.

Abstract: A homogenous sample of identical bispecific antibody determinants, each determinant being composed of two L-H half-molecules linked by disulfide bonds, each L-H half-molecule being specific for a different antigenic determinant and including at least the F(ab') portion of a monoclonal IgG antibody. The bispecific antibody determinants are useful, e.g., in the formation of multilamellar assemblies and enzyme electrodes.

Abstract: In the immunoassay of antigens in liquids, a reaction mixture is formed containing the liquid under assay, labelled antigen, and a mixed binding reagent which contains an antigen-binding site and a label-binding site, the two sites being spaced apart in the reagent so that a single molecule of labelled antigen cannot bind to both sites. The label is one whose activity is changed upon binding to a label-binding site, and the amount of antigen in the original liquid sample is determined by measuring the activity of the label in the reaction mixture. A preferred label is a fluorophore. The mixed binding reagent preferably consists of two antibodies linked together.