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: This invention provides (1) a reagent for endotoxin assay which comprises aprotinin and a limulus amebocyte lysate reagent, (2) a kit for endotoxin assay which comprises the limulus amebocyte lysate reagent and a reagent containing aprotinin, (3) a method for assaying endotoxin in a sample using the limulus amebocyte lysate reagent in which aprotinin is added to the lysate reagent and/or the sample, (4) a method for assaying endotoxin in a serine protease-containing sample using the limulus amebocyte lysate reagent in which the sample is allowed to contact with an aprotinin-immobilized insoluble carrier in advance of endotoxin assay, (5) a carrier for pretreating a serine protease-containing sample on which aprotinin is immobilized, (6) a method for inhibiting factor G activation in which aprotinin is added to the limulus amebocyte lysate reagent and (7) a factor G activation inhibitor which comprises aprotinin as an active ingredient.

Abstract: The estrogen-regulated gene sequence pLIV1 has been discovered and isolated, and found to be significantly associated with the metastatic spread of breast cancer cells to the regional lymph nodes. Methods are therefore provided for determining the risk of metastasis of a female breast tumour, as well as for predicting the responsiveness to endocrine treatment of a female breast tumour, which involve determining whether a tissue sample from a tumour expresses a polypeptide containing the pLIV1 gene sequence, or a substantial portion thereof.

Abstract: Improvements in the existing procedures and materials for conduct of high gradient magnetic separation (HGMS) are disclosed. Superior superparamagnetic particles, optionally coated with a polysaccharide or other, usually organic, materials can be prepared in uniform compositions with homogeneous magnetizations. The coating can conveniently be conjugated to a specific binding moiety complementary to a biological material whose purification or separation is desired. In addition, plastic coated matrices which form superior magnetic gradient-intensifying supports are disclosed, along with improved methods and apparatus to conduct HGMS.

Abstract: This disclosure concerns a method of detecting the presence of a polypeptide in a sample wherein the polypeptide is encoded by a fragment of a nucleic acid molecule encoding an amyloid precursor mutein and the fragment comprises a sequence encoding at least one marker and a sequence encoding about 419 amino acid residues of the APP-695 isoform, about 475 amino acid residues of the APP-751 isoform or about 494 amino acid residues of the APP-770 isoform. The method encompasses contacting the sample with an antibody, which specifically binds the marker or the amyloid precursor mutein, under suitable conditions to favor the formation of an antibody-antigen complex and detecting the presence of any complex thus formed. The disclosure also deals with the method employing the above nucleic acid fragment wherein the amino acid residues from position 11 to position 28 are deleted from the portion of the sequence encoding the .beta.

Abstract: A system and method is disclosed employing a full thickness skin model for determining minimum sun protection factors (SPFs) of various sunscreen formulations by measuring the release of an inflammatory mediator in the skin model.

Abstract: Methods of assaying samples for the presence of an analyte involving immobilization of a gold sol, and optionally an enzyme capable of generating a reaction product, on a solid phase. The gold sol has a mean particle size of less than 20 nm for at least 75% by weight of the particles and is formed into a novel superaggregated complex with at least one protein.

Abstract: The present invention provides novel methods of screening for ulcerative colitis and Crohn's disease which include the detection of two disparate autoantibodies: pANCA and VH3-15 autoantibody. The present invention also provides kits for screening ulcerative colitis and Crohn's disease.

Abstract: SLO peptide antigens are described. These peptide antigens are suitable for the determination of SLO antibodies, as immunogens for the production of antibodies against SLO and as vaccines for the production of vaccines against SLO.

Abstract: Methods of determining collagen degradation in vivo, by quantitating the concentration of a peptide in a body fluid, the peptide having the following structure: ##STR1## is hydroxylysyl pyridinoline or lysyl pyridinoline, and J is pyroglutamic acid or glutamine and (Leu) are optional leucines, are disclosed.

Abstract: A dry immunoassay analytical element for assaying a ligand, comprising a support bearing:1. an enzyme labeled ligand or an enzyme labeled receptor zone;2. a spreading zone; and3. a receptor zone containing a fixed concentration of an immobilized receptor for the ligand and the labeled ligand when present and the receptor is covalently bonded to polymeric beads having a diameter in the range of 0.1 to 5 .mu.m; characterized in that the element contains a diaryl telluride (DAT) compound and the zones can be in the same or separate layers.

Abstract: A method is disclosed for stabilizing a conjugate of an enzyme and a member of a specific binding pair (enzyme conjugate). The method comprises the step of combining the enzyme conjugate with an effective amount of an antibody for the enzyme where the antibody does not substantially inhibit the activity of the enzyme. The invention has application to assays for the determination of an analyte wherein enzyme conjugates are employed. The improvement comprises employing as a reagent in the assay an immune complex of an enzyme conjugate and an antibody for the enzyme where the antibody does not substantially inhibit the activity of the enzyme. Compositions comprising such an immune complex and kits comprising such an immune complex in packaged combination with other assay reagents are also disclosed.

Abstract: A chemiluminescent assay method, compositions and kits are described which use a protected phenolic enhancer compound which is deprotected by a hydrolytic enzyme and then enhances a chemiluminescent reaction. The reaction involves an acridan compound, preferably a derivative of an N-alkylacridan-9-carboxylic acid, which is activated to produce light by a peroxide compound and a peroxidase enzyme in the presence of the deprotected enhancer. The result is enhanced generation of light from the reaction. The hydrolytic enzyme is present alone or linked to a member of a specific binding pair in an immunoassay, DNA probe assay or other assay where the hydrolytic enzyme is bound to a reporter molecule.

Abstract: Sensitive methods using a variety of biomarkers in oral saliva of humans and animals to detect measure, and quantify the presence of infectious and non-infectious agents and the functional status of living tissues in both (1) biomedical and (2) environmental applications. With in vivo biomedical applications, saliva samples are taken from human and animals and biomarker, such as enzyme or antibody levels, are measured. The extent of exposure to an agents is measured by the presence of specific chemical or biological constituents, by the degree of enzymes inhibition, or by the changes in the amount of the biochemicals in saliva. With in vitro environmental applications, enzymes or other biochemicals from animal or human saliva can be used to monitor the presence of toxic or reactive agents in tissue samples, urine, feces, milk, air, water, soil, or plants. The amount of toxicant in samples is estimated from a standard curve for that agent.

Abstract: The invention provides an apparatus for performing a process for amplification of specific nucleic acid sequences based upon the separation of nucleic acid strands by an electromagnetic field. This means of separation allows the use of mesophilic polymerases in the amplification process, thereby increasing the speed and fidelity of the amplification process, as well as the size of target nucleic acid that can be amplified.

Abstract: The present invention relates to the field of immunossays for metal ions. The invention presents: metal ion-ligand coordination complexes ("MLC"), novel ligands, antibodies specific for MLC, immunoassays utilizing the foregoing, and methods for selecting said antibodies.

Abstract: Disclosed is a gene situated in the region of the neuroblastoma consensus deletion 1p36.2-p36.1 which codes for a helix-loop-helix protein with the designation HEIR-1. The loss of this gene is significantly correlated with allelic tumor deletions in neuroblastomas and expression of this correlates inversely both N-myc overexpression in tumors and with N-myc expression in normal development. The cDNA and antibodies coding for HEIR-1 are used for the diagnosis of pathological conditions associated with aberration in the region of the neuroblastoma consensus deletion.

Abstract: A method of immunologically assaying intact human osteocalcin in a human assay sample is provided by using an antibody having an epitope in a region of an amino acid sequence 1 to 20 on the N-terminal side of human osteocalcinand an antibody having an epitope in a region of an amino acid sequence 36 to 49 on the C-terminal side of human osteocalcin. Furthermore, a method of immunologically assaying the total amount of human intact osteocalcin in a human assay sample is provided. A reagent and a kit therefor are also described, as well as a monclonal antibody and a polyclonal antibody used for the assay a process for producing these antibodies; and a process for use of these antibodies.

Abstract: A method for increasing the binding activity of specific binding members bound to a solid phase material, e.g., a particle, that has been sterically stabilized. This increase in binding activity is brought about by degrading a steric stabilizer on the surface of the solid phase material. The method involves both immobilizing a specific binding member on the surface of a solid phase material and degrading a steric stabilizer on the surface of that solid phase material. In the preferred embodiment, the method involves the immobilization of a specific binding member on the surface of the sterically stabilized solid phase material, with subsequent degradation of the steric stabilizer.

Abstract: This invention is directed to a ligand-receptor assay for determining the presence of at least one target ligand, capable of competing with a ligand analogue conjugate for binding sites available on a ligand receptor, said ligand analogue conjugate comprising at least one ligand analogue coupled to a colloidal gold particle, in a fluid sample suspected of containing said target ligand comprising the steps of:a. contacting said fluid sample with said ligand analogue conjugate and said ligand receptor to form a homogeneous reaction mixture, the relative amounts of said ligand analogue conjugate and said ligand receptor being selected such that in the absence of said target ligand and subsequent to substantially equilibrium binding in said reaction mixture, substantially all of said ligand analogue conjugate is bound to said ligand receptor such that no unbound ligand analogue conjugate is detected as a result of the assay method;b.

Abstract: An apparatus for collecting antigen, including an allergen exemplified by a dust-mite, dispersed in a motile fluid in a given environment that can be inserted in a section of a pipe of a standard vacuum cleaner hose. The apparatus includes a receptacle whose body is formed of nylon, typically with a pore size of from 15 to 60 .mu.m. The receptacle is coated with an antibody that retains the antigen in a contacting relationship. The apparatus is provided with a removable holder, which assists in locating the apparatus in the pipe of the vacuum cleaner. The apparatus can be used directly in an immunoassay for confirming the presence of, or quantifying, the antigen.

Abstract: A nucleotide probe complex which enhances the ability to discriminate low level samples in electrochemiluminescent assays. The complex is composed of a platform molecule to which multiple copies of an organometallic electrochemiluminescent label and an oligonucleotide probe are separately attached. Preferably the complex is capped with streptavidin. Use of the complex permits detection of 1000 copies of analyte per sample in less than one hour.

Abstract: A chemiluminescent method is provided for the analysis of a target. A peroxidase is first bound as a labelling substance to the target by using a target specific binding reagent. The target so labelled is isolated and then reacted with luminol, hydrogen peroxide and an enhancer in an aqueous solvent. The luminescence of light is detected and measured. The aqueous solvent contains at least one protein selected from the group consisting of skim milk and egg albumin. Preferably, the aqueous solvent also contains a non-ionic surfactant such as a polyoxyethylene ether and/or a sugar alcohol such as mannitol.

Abstract: Marker components are provided which are compatible with aqueous solutions, exhibit favorable fluorescence properties and exhibit decreased non-specific binding to macromolecules in solution. These marker components are useful in applications such as fluorescence immunoassays and in vivo imaging.

Abstract: Method of assay of enzymatic activity, comprising projecting excitation light to a sample containing an enzyme, a substrate which forms a product by action of the enzyme, and a reference substance which is insensitive to the action of the enzyme but emits fluorescence; obtaining a first measured value of fluorescence intensity of the sample at a first wavelength region which includes fluorescence emitted by the substrate or the product at least, obtaining a second measured value of fluorescence intensity at a second wavelength region which is different from the first wavelength region for the first measured value and includes fluorescence emitted by the reference substance; and assaying the enzymatic activity from the ratio of the first measured value to the second measured value and apparatus for performing the method. The method assures high accuracy and high sensitivity of measurement in enzyme labeled immunoassay and enzyme labeled DNA hybridization.

Abstract: Two amino acid sequences are joined together using an electron acceptor moiety and a linking moiety, such as a chelating agent. In particular, an amino acid sequence specific for binding to a material interest is linked to an enzyme which acts on an indicator, such as a colorimetric, phosphometric, fluorometric or chemiluminescent substrate. The linking composition is useful in immunoassays.

Abstract: A 65 KD heat shock protein, proteins cross-reactive therewith, or antibodies thereto can be used for detecting in humans the existence of, a tendency to develop, or the initiation of a process leading to insulin dependent diabetes mellitus. Antibodies to hsp65 can be used to detect the hsp65 molecule in blood or urine. The hsp65 molecule of any species, or any other substance immunologically cross-reactive therewith, when administered with a tolerogenic carrier, can be used for the prevention or treatment of IDDM prior to development of clinical symptoms thereof.

Abstract: A non-radioactive method of detecting the enzymes beta galactosidase or beta glucosidase directly or for the detection of a ligand and antiligand complex is provided wherein beta galactosidase or the complex labelled with beta galactosidase or a tracer having beta galactosidase conjugated thereto is reacted with 5-bromo-4-chloro-3-indolyl-B-D-galactoside and a tetrazolium salt to produce a colored formazan or a color change indicative of the presence of beta galactosidase, or wherein beta glucosidase or the complex labelled with the beta glucosidase or a tracer having beta glucosidase conjugated thereto is reacted with 5-bromo-4-chloro-3-indolyl-B-D-glucoside and a tetrazolium salt to produce a colored formazan or a color change indicative of the presence of beta glucosidase. Optionally, the galactosidase-galactoside determination or the glucosidase-glucoside determination may further include catalyst phenazine methosulfate (PMS) as a reactant.

Abstract: Peptides corresponding to epitopes of HTLV-2 proteins are provided. These peptides are immunologically reactive with HTLV-2 specific antibodies. Several of the peptides are sufficiently unreactive to antibodies to HTLV-1 to distinguish between antibodies which recognize HTLV-1 and those which recognize HTLV-2. Thus HTLV-1 infections can be distinguished from HTLV-2 infections. The peptides are useful in assays for detection of HTLV-2 infection or exposure. The peptides are also useful as vaccine compositions against HTLV-2. Antibodies generated in response to immunization by the peptides are also provided.

Abstract: A method and kit for measurement of asteroid by means of a competitive immunoassay, preferably a competitive enzyme immunoassay. The method and kit involve the use of asteroid analogue conjugated to a label. The steroids that are amenable to detection by the method and kit of the present invention include estradiol and progesterone.The method comprises the steps of:a. incubating a mixture of a test sample suspected of containing a given steroid, a solid phase coupled to an antibody specific for that steroid, and a conjugate of an analogue of that steroid to form steroid/antibody complexes and conjugate/antibody complexes on said solid phase;b. separating said solid phase from said mixture;c. measuring the amount of label present in said mixture or in said solid phase; andd. determining the amount of steroid in said sample from the amount of label.The kit comprises a solid phase coupled to an antibody specific for a steroid and a conjugate of an analogue of that steroid.

Abstract: A method for determining the presence and/or concentration of a target substance e.g. protein, nucleic acid, bioparticle etc. in a fluid sample is provided. The method disclosed combines elements of immunoassays, coated cup assays and magnetic particle separation to effect the quantitation and recovery of an analyte in solution. Also the method ensures the non-reorientation of magnetically collected material by linking the magnetic particles to a collection surface via a specific binding pair. This linkage immobilizes the magnetic-analyte-containing material and thus allows for vigorous washing and reagent addition without significant redistribution or displacement. Thus the assay of this invention offers the speed of diffusion controlled kinetics as in a ferrofluid assay, the speed of collection of labeled target substance as in a magnetic assay as well as the ability to magnetically monolayer the ferrofluid, all of which is combined with the ease of washing and signal detection found in a coated cup assay.

Abstract: A trifunctional conjugate is providing 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 moieties sterically inhibits the binding of a different macromolecule to another chemical moieties. In another embodiment, the binding of a first chemical moiety to a macromolecule restricts the subsequent binding of a second tridentate member to a proximate location on the same macromolecule. The three chemical moieties are preferably a nitrophenylazido residue, a phenyl boronic acid residue, and a solid support or a label such as biotin. The spacer is preferably cysteine, lysine, glutamic acid, pyroglutamic acid, S-acetylmercaptosuccinic anhydride or .omega.-carbobenzoxylysine.

Abstract: A disposable diagnostic assay device and method for its use are provided. The device comprises a sample addition port in fluid communication with at least one main channel. The main channel comprises, in the direction of fluid flow, a main reagent area in fluid communication with an incubation area and a waste area. In fluid communication with the main channel is at least one side reagent channel. The side reagent channels comprise, in the direction of fluid flow, a liquid addition port and a side reagent area in fluid communication with the main channel at a region of the main channel upstream from the incubation area. Agitation means may be included in the at least one of the main and side reagent areas and/or the incubation area. Capillary valves may be located at various positions along the main and side reagent channels upstream from the incubation area, providing for control over fluid flow through the device.

Abstract: The invention relates to a new antigen termed BLA-36 specifically expressed on the surface of Hodgkin's cells, Reed-Sternberg cells and B lymphocytes, and to a new monoclonal antibody (anti-BLA-36) specific thereto. The antigen is characterized by the following properties:a molecular weight of about 36,000 D;the presence of an epitope recognized by antibody to said protein;specific expression by Hodgkin's cells and Reed-Sternberg cells in all subsets of Hodgkin's disease, and by activated and early proliferating B cells;no expression by T cells;capability of reacting with its antibody in both frozen and fixed/paraffin embedded tissues;a function associated with the growth of cells capable to express said antigen protein.

Abstract: This invention relates to a monoclonal antibody having affinity to human TCF-II without any affinity to HGF and determination or purification methods of TCF-II using the antibody. The monoclonal antibody can be obtained by adding a blocking solution containing a surface active agent to the culture medium containing monoclonal antibody to block antibodies other than said monoclonal antibody, followed by reaction with a solid phase antigen, TCF-II. Human TCF-II can be selectively and effectively purified or determined without any influence of the presence of HGF by using the antibody.

Abstract: The invention pertains to dipstick immunoassay devices. The device comprises a base member and a single, combined sample contact zone and test zone, wherein the test zone incorporates the use of symbols to detect analytes in a sample of biological fluid. A first immunological component, an anti-immunoglobulin capable of binding to an enzyme-labeled antibody, is immobilized in a control indicia portion. A second immunological component, capable of specifically binding to a target analyte which is bound to the enzyme-labeled antibody to form a sandwich complex, is immobilized in a test indicia portion. The enzyme-labeled antibody produces a visual color differential between a control indicia portion and a non-indicia portion in the test zone upon contact with a substrate.

Abstract: A method and apparatus are disclosed for identifying molecular structures within a sample substance using a monolithic array of test sites formed on a substrate upon which the sample substance is applied. Each test site includes probes formed therein to bond with a predetermined target molecular structure or structures. A signal is applied to the test sites and certain electrical, mechanical and/or optical properties of the test sites are detected to determine which probes have bonded to an associated target molecular structure.

Abstract: The present invention relates to the field of immunoassays for metal ions. The invention presents: metal ion-ligand coordination complexes ("MLC"), novel ligands, antibodies specific for MLC, immunoassays utiliizing the foregoing, and methods for selecting said antibodies.

Abstract: A method for diagnosing prostate cancer in a mammal is described. Serum from a mammal is provided. PSA is added to this serum, and the amount of ACT-PSA complex formed is measured. It is determined if the mammal has prostate cancer based on the amount of ACT-PSA complex that is formed. An isolated prostate cancer specific form of ACT which is capable of forming a stable complex with PSA is also described.

Abstract: The present invention provides a method of diagnosing and treating a pregnant female at risk for impending preterm delivery. The method comprises the step of diagnosing imminent preterm delivery by testing with a method that has a sensitivity of at least 80% and a specificity of at least 80%, or by testing for fetal fibronectin in the female's vaginal or cervical secretions. If imminent preterm delivery is indicated by the test, the next step comprises administering to the female a combination of a tocolytic agent, at least one urinastatin-like compound, and at least one antibiotic. Also provided is a pharmaceutical composition of MGMTSRYFYNGTSMA (SEQ ID NO:1), RAFIQLWAFDAVKGK (SEQ ID NO:2) and an antibiotic.

Abstract: Methods of assaying samples for the presence or quantity of an analyte involving immobilization of a gold sol, and optionally an enzyme capable of generating a reaction product, on a solid phase. The gold sol has a mean particle size of less than 20 nm for at least 75% by weight of the particles and is formed into a novel superaggregated complex with at least one protein.

Abstract: Methods and compositions for detecting and localizing light originating from a mammal are disclosed. Also disclosed are methods for targeting light emission to selected regions, as well as for tracking entities within the mammal. In addition, animal models for disease states are disclosed, as are methods for localizing and tracking the progression of disease or a pathogen within the animal, and for screening putative therapeutic compounds effective to inhibit the disease or pathogen.

Abstract: The subject invention provides an antibody which specifically binds to the product of a reaction between a labeling substance and a substrate. The subject invention also provides a method of making an immunogen used to produce the antibody of the subject invention. The invention further provides methods of using the subject antibody for detecting an antigen of interest in a sample, for example detecting a protein comprising an amino acid sequence of interest and detecting a nucleic acid molecule comprising a nucleic acid sequence of interest.

Abstract: The present invention encompasses a method of synthesis of conjugates of photoproteins that retain all or a substantial portion of the luminescent activity of underivatized photoprotein. According to the present invention photoproteins may be conjugated with a variety of binding reagents including streptavidin/avidin, glycoproteins, lectins, hormones, antigens, drugs, antibodies and antigen binding fragments thereof, or any other selectively bindable reagent by chemical crosslinking means. The present invention also encompasses conjugates produced by this method, and methods of use of such conjugates.

Abstract: A chromatographic assay device for detection and/or determination of an analyte in a competitive immunoassay gives a semiquantitative or quantitative indication of analyte concentration in a single assay device while also giving a positive indication that flow has occurred properly through the device. In one form, the device comprises: (1) a first opposable component including a sample preparation zone and an absorber; and (2) a second opposable component including a first chromatographic medium with capture and detection zones, a second chromatographic medium with a comparison zone, and a comparison label. In another form, the second opposable component includes one chromatographic medium with capture, detection, and control zones. Test kits incorporating the devices and methods for their use are also disclosed.

Abstract: Specific peptide fragment from the feline immunodeficiency virus (FIV), and its use as a diagnostic reagent.The said peptide fragment, derived from the Env protein of the Wo strain of the feline immunodeficiency virus (FIV) (peptide P253), corresponds to positions 693-709 of the said Env protein and exhibits the following sequence:Leu-Gly-X-Asn-Gln-Asn-Gln-Phe-Phe-X-Lys-Val-Pro-Ser-Ala-, in which X represents a cysteine or a serine, as follows:Leu-Gly-Cys-Asn-Gln-Asn-Gln-Phe-Phe-Cys-Lys-Val-Pro-Ser-Ala (SEQ ID NO: 1),Leu-Gly-Ser-Asn-Gln-Asn-Gln-Phe-Phe-Ser-Lys-Val-Pro-Ser-Ala (SEQ ID NO: 2),Leu-Gly-Cys-Asn-Gln-Asn-Gln-Phe-Phe-Ser-Lys-Val-Pro-Ser-Ala (SEQ ID NO: 3),Leu-Gly-Ser-Asn-Gln-Asn-Gln-Phe-Phe-Cys-Lys-Val-Pro-Ser-Ala (SEQ ID NO: 4).

Abstract: Apparatus and method for simultaneously performing at least two assays using certain reagents for a plurality of liquid samples on a continuous analytical system is disclosed. The method comprising the steps of combining an aliquot of each liquid sample with at least one reagent in a first reaction container to form a first assay reaction for each liquid sample, and combining an aliquot of each liquid sample with at least one of the other reagents in a second reaction container to form a second assay reaction for each liquid sample. The method further comprises the steps of incubating the assay reactions of each assay being conducted at least one time, and performing other activities associated with each assay and using the first and second assay reactions to complete each assay, including analyzing the incubated assay reactions.

Abstract: This invention relates to improved methods and novel compositions for enzyme complementation assays for qualitative and quantitative determination of a suspected analyte in a sample. The use of enzyme-acceptor and enzyme-donor polypeptides prepared by recombinant DNA techniques, DNA synthesis or chemical polypeptide synthesis techniques which are capable of interacting to form an active enzyme complex having catalytic activity characteristic of .beta.-galactosidase is described. Both homogeneous and heterogeneous assays utilizing these polypeptides are described.

Abstract: The invention relates to a method of using a pair of leucine zipper peptides for in vitro diagnosis, in particular, for the immunochemical detection and determination of an analyte in a biological liquid. In one method, the first leucine zipper peptide is immobilized by attaching it to a solid support, the second leucine zipper peptide is coupled to a specific binding partner for the analyte, the two peptides are brought into contact, the sample of the biological liquid is brought into contact with the immobilized first peptide and the specific binding partner for the analyte, and the amount of analyte bound to the binding partner is determined. The leucine zipper peptides are preferably v-fos and c-jun.

Abstract: There are disclosed a hybridoma obtained by fusing a myeloma cell with an anti-thymosin .alpha.1 antibody-producing cell and selecting a hybridoma which produces a monoclonal antibody that recognizes the N-terminus of thymosin .alpha.1; an anti-thymosin .alpha.1 monoclonal antibody which is produced by the hybridoma, and a method for measuring thymosin .alpha.1 which comprises forming a three-component complex comprising thymosin .alpha.1, the anti-thymosin .alpha.1 monoclonal antibody (A), and an anti-thymosin .alpha.1 antibody (B) that recognizes a different site of thymosin .alpha.1 than antibody (A) does; forming a four-component complex of said three- component complex with a labeled substance (C) that specifically binds to antibody (A) or antibody (B) of the three-component complex; and detecting the labeled substance in said four-component complex.