Abstract: Artificial antibodies or antibody mimics are described. They consist of polymers that carry specific binding sites mimicking the properties of antibodies. There is also described a method for producing artificial antibodies, in which polymerisable monomers carrying functional groups and crosslinking monomers are polymerised in the presence of a print molecule and subsequently the print molecule is removed leaving specific binding sites complementary to the print molecules. There are also described methods for determination and isolation of organic molecules using the artificial antibodies as well as therapeutic and diagnostic methods using these antibodies.

Abstract: Provided are a method for easily detecting phosphorylated peptides, namely, proteins, in samples derived from living organisms or the like, a method for selectively adsorbing the phosphorylated peptides, and compounds that are highly coordinated to the phosphorylated peptides and usable in the methods. The complex compound is represented by the formula: wherein X is a linker moiety, and Y is a labeling group. The compound (I) is highly coordinated to a phosphorylated peptide, and has a labeling group. Accordingly, with use of the compound (I), the phosphorylated peptide can be easily identified.

Abstract: A fluorescent label compound of formula where Z is a reactive group that can be used for covalent coupling of the fluorescent label compound to other molecule. Either the fluorophore is a dipyrrometheneboron difluoride dye and Y is a water-solubilizing moiety, or Y is —CH2CH2SO3? X+ where X+ is a cation. The use of the compounds in bianalytical assays and cytological or histological staining methods, and a method for increasing the hydrophilicity of fluorescent compounds, are also disclosed.

Abstract: The present invention relates to monoclonal antibodies that specifically bind buprenorphine and/or at least one metabolic product thereof. The present invention further relates to buprenorphine metabolite conjugates for the production of monoclonal antibodies that specifically bind buprenorphine and/or at least one metabolic product thereof and hybridoma cells that produce the monoclonal antibodies. The invention also relates to immunoassay methods for determining buprenorphine and/or one or more buprenorphine metabolites in a sample using the novel antibodies and conjugates of the present invention.

Abstract: Activated haptens useful for generating immunogens to HIV protease inhibitors, immunogens useful for producing antibodies to HIV protease inhibitors, and antibodies and labeled conjugates useful in immunoassays for HIV protease inhibitors. The novel haptens feature an activated functionality at the central, non-terminal hydroxyl group common to all HIV protease inhibitors, e.g., saquinavir, nelfinavir, indinavir, amprenavir, ritonavir, lopinavir, and atazanavir.

Abstract: The present invention relates to a method for preparing haptens of formulae I and II that are useful in the preparation of immunogens, antibodies and conjugates, for use in competitive immunoassays for the detection of ractopamine, isoxsuprine and ritodrine. The haptens are prepared by reacting a phenylethanolamine derivative of formula D with a phenylalkylcarbonyl derivative of formula E: in which, in formula I, Z1 is a crosslinker and Z2 is H and, in formula II, Z1 is H and Z2 is a crosslinker.

Abstract: New derivatives of FK 506 are disclosed. These new derivatives and other derivatives that are useful for determining the levels of FK 506 in a sample are also provided as are assay procedures and kits for use in determining the levels of FK 506 or other macrophilin binding substances in blood, particularly un-extracted blood in the presence of specific binding proteins for FK 506.

Abstract: Methods are disclosed for producing electrochemiluminescence by electrochemically oxidizing an acridan compound at an electrode in the presence of a peroxide. Maintaining a sufficiently positive potential results in continuous oxidation of the acridan compound to an acridinium compound which reacts with peroxide to produce the luminescence. Light emission can be reversibly and repeatedly cycled on and off by sweeping the potential between two values. The acridan compounds can be provided with a labeling group for linking to an analyte or analyte binding partner. The present electrochemiluminescent reaction can find use in assay methods for detecting analytes by immunoassays and nucleic acid assays.

Abstract: The invention provides peptide synthons having protected functional groups for attachment of desired moieties (e.g. functional molecules or probes). Also provided are peptide conjugates prepared from such synthons, and synthon and conjugate preparation methods including procedures for identifying optimum probe attachment sites. Biosensors are provided having functional molecules that can locate and bind to specific biomolecules within living cells. Biosensors can detect chemical and physiological changes in those biomolecules as living cells are moving, metabolizing and reacting to its environment. Methods are included for detecting GTP activation of a Rho GTPase protein using polypeptide biosensors. When the biosensor binds GTP-activated Rho GTPase protein, an environmentally sensitive dye emits a signal of a different lifetime, intensity or wavelength than when not bound.

Abstract: Disclosed are cyanine dyes having meso-substituents in the polymethine chain linking the heterocyclic ring systems. The dyes are of formula (1): in which groups R3 and R4 are attached to the Z1 ring structure and groups R5 and R6 are attached to the Z2 ring structure, and n=1, 2 or 3; Z1 and Z2 independently represent the atoms necessary to complete one ring, or two fused ring aromatic or heteroaromatic systems, each ring having five or six atoms selected from carbon atoms and optionally no more than two atoms selected from oxygen, nitrogen and sulphur; X and Y are the same or different and are selected from oxygen, sulphur, —CH?CH— and the group: at least one of groups R1, R2, R3, R4, R5, R6 (and R8 and R9 if present) is the group -E-F where E is a spacer group and F is a target bonding group; one of groups R7 is selected from —CN, —Cl, —F, —CF3 and —C(O)R10 wherein R10 is selected from H, C1–C6 alkyl and aryl.

Abstract: Compounds including haptens, intermediates, and immunogens that are useful in the production of antibodies specific for the methylenedioxy class of amphetamine derivatives are described. Antibodies specific for the methylenedioxy class of amphetamine derivatives, reagent kits containing antibodies specific for the methylenedioxy class of amphetamine derivatives, methods of producing antibodies specific for the methylenedioxy class of amphetamine derivatives, and methods of detecting analytes including members of the methylenedioxy class of amphetamine derivatives are also described.

Abstract: A method having clinically sufficient degree of diagnostic accuracy for detecting the presence of coronary artery disease in a human patient from the general population and for distinguishing between the stages of the disease in that patient is disclosed. The stages are, first, the non-acute stage, which is either asymptomatic coronary artery disease or stable angina, second, the acute stage known as unstable angina, and, third, the acute stage known as acute myocardial infarction. The diseased state (as opposed to the non-diseased state) is indicated by the clinically significant presence of a first marker in a sample from the patient. The presence of one of the two acute stages, unstable angina or acute myocardial infarction, is indicated by the clinically significant presence of a second marker in a sample from the patient. The presence of the more severe acute stage known as acute myocardial infarction is indicated by the clinically significant presence of a third marker in a sample from the patient.

Abstract: The present invention describes methods and cassettes for cell-based toxin detection and organ localization. The cassettes includes an array containing cells and a matrix of openings or depressions, wherein each region of the substrate enclosed by the opening or depression in the matrix forms a domain individually addressable by microfluidic channels in the device.

Abstract: Compositions and methods are disclosed for detecting multiple target analytes in a sample using microparticles having molecular tags attached by cleavable linkages. Generally, an assay mixture is formed comprising a sample and a reagent comprising multiple such microparticles under conditions that permit stable complexes to form between binding moieties on the surfaces of the microparticles and the analytes. In one aspect of the invention, the a second binding composition is added so that complexes form among the microparticle-bound binding moieties, the analytes, and second binding moieties of the second binding composition. Such second binding moieties have cleavage-inducing moieties attached that upon activation cause the cleavage of the cleavable linkages and the release of molecular tags. Released molecular tags are separated and the presence and/or amount of the target analytes are determined based on the analysis of the released and separated molecular tags.

Abstract: Activated haptens useful for generating immunogens to the HIV protease inhibitor atazanavir, immunogens useful for producing antibodies to atazanavir, and antibodies and labeled conjugates useful in immunoassays for determination of atazanavir. The haptens feature an activated functionality at the central, non-terminal hydroxyl group.

Abstract: A microscale binding assay, analyte binding array, and kits are disclosed, which exploit the mass action law to harvest analyte from a liquid sample. This is achieved by fabrication of sorbent zones having up to ten times the binding capacity per unit area generally obtained on polystyrene microtiter plates. The resulting arrays substantially deplete the liquid solution of analyte during incubation. Accordingly, the assays respond to total mass of analyte in the sample, not analyte concentration. This approach, coupled with direct fluorescence detection in the NIR, yields maximal signal intensity and low background for optimal sensitivity.

Abstract: Solid-state colorimetric biosensors having sensory groups and interdendritic cross-linking segments of alternating conjugated double and triple bonds are prepared by intermolecular polymerization of diacetylene-functionalized dendritic polymer precursors. The polymerization process may be used to form solid films that are capable of indicating the presence of an analyte by a detectable change in color. The disclosed solid-state colorimetric biosensors may exhibit excellent stability at elevated temperatures and in the presence of organic solvents, and due to the dendritic architecture and high density of sensing functionality achieve high sensitivity to analytes.

Abstract: The invention teaches derivatives of mycophenolic alcohol and methods of preparing immunogens and other conjugates useful in immunoassays for quantitatively measuring concentrations of mycophenolic acid (MPA) and/or active metabolites of MPA in patient specimens. Antibodies produced from the disclosed immunogens capable of binding to MPA with cross-reactivity of no more than 5% with inactive metabolites and commonly co-prescribed drugs. Further, immunoassays for measuring the concentration of MPA using such antibodies are taught.

Abstract: The present invention concerns coupling agents having the following general formula: activated intermediates consisting of a coupling agent such as defined above with either a molecule having on its surface at least one aldehyde and/or ketone function before conjugation, or with one to eight molecules having on their surface at least one free thiol function before conjugation, conjugates consisting of a coupling agent such as defined above, of a molecule having on its surface at least one aldehyde and/or ketone function and of one to eight molecules having on their surface at least one free thiol function, and the use of said conjugates for in vitro diagnostic methods of diseases involving recognition of a ligand-anti-ligand pair.

Abstract: Methods, compositions and kits are disclosed. The compounds disclosed comprise an amphetamine moiety and a methamphetamine moiety linked together by a first linking group. A second linking group depends from the first linking group and comprises a functional group. The distance of the amphetamine moiety and the methamphetamine moiety from the point of linkage of the second linking group to the first linking group is approximately the same. The compounds may be linked to labels and used in assays for the detection of amphetamine and/or methamphetamine in samples suspected of containing these drugs.

Abstract: The invention provides a hapten derivatized with a crosslinker at the nitrogen of the 8?-carboxamide of 2-oxo-3-hydroxy LSD. The invention also provides an immunogen comprising the aforementioned hapten coupled to an antigenicity-conferring carrier material; a conjugate comprising the aforementioned hapten coupled to a labelling agent, as well as, antibodies raised against the aforementioned immunogen and capable of binding with at least the 3-hydroxy-2-pyrrolidone structural epitope of 2-oxo-3-hydroxy LSD.

Abstract: The invention provides an immunogen comprising a hapten coupled to an antigenicity-conferring carrier material, a conjugate comprising the aforementioned hapten coupled to a labelling agent, as well as, antibodies raised against the aforementioned immunogen and capable of binding with at least one structural epitope of metabolites of fentanyl and of metabolites of fentanyl analogs.

Abstract: A fluorescent probe for measuring magnesium ion, which can selectively form a complex with magnesium ion in aqueous system is disclosed. The fluorescent probe for measuring magnesium ion according to the present invention has the structure represented by the following Formula [I]: (wherein R1 represents a hydrogen atom, metal atom or an ester-forming group; A represents a group which forms a ring structure together with carbon atom 1 and carbon atom 2; and X is a fluorescent group which may form a condensed ring together with the ring containing the group A).

Abstract: Compounds including haptens, intermediates, and immunogens that are useful in the production of antibodies specific for the methylenedioxy class of amphetamine derivatives are described. Antibodies specific for the methylenedioxy class of amphetamine derivatives, reagent kits containing antibodies specific for the methylenedioxy class of amphetamine derivatives, methods of producing antibodies specific for the methylenedioxy class of amphetamine derivatives, and methods of detecting analytes including members of the methylenedioxy class of amphetamine derivatives are also described.

Abstract: The invention relates to oxazine derivatives by means of which a broad spectrum of material to be examined can be marked and identified using fluorescence techniques.

Abstract: The invention provides isolated nucleic acid molecules and polypeptide molecules that encode glycoprotein VI, a platelet membrane glycoprotein that is involved platelet-collagen interactions. The invention also provides antisense nucleic acid molecules, expression vectors containing the nucleic acid molecules of the invention, host cells into which the expression vectors have been introduced, and non-human transgenic animals in which a nucleic acid molecule of the invention has been introduced or disrupted. The invention still further provides isolated polypeptides, fusion polypeptides, antigenic peptides and antibodies. Diagnostic, screening and therapeutic methods utilizing compositions of the invention are also provided.

Abstract: This invention relates to the field of internal quality control in diagnostic analysis, particularly in the analysis of microorganisms or other small particles, such as the detection of bacteria, protozoa, yeast, fungi, viruses, prions and the like, in water or other potable fluids, food, blood, urine, faeces, cerebro spinal fluid, and the like.

Abstract: A chemiluminescence method characterized in that when a 1,2-dioxetane derivative of the formula 1: wherein each of R1, R2, R3, R4 and R5 which are independent of one another, is a hydrogen atom, an alkyl group or an aryl group, or each pair of R2 and R3, and R4 and R5, which are independent of each other, may form together a cyclic alkyl group, R6 is a hydroxyl group, an alkoxyl group, an aralkyloxy group, a group represented by —OSi(R8R9R10) (provided that each of R8, R9 and R10 which are independent of one another, is an alkyl group or an aryl group), a phosphate group or a group represented by S(C?O)R11 (provided that R11 is an alkyl group or an aryl group), and R7 is a hydrogen atom, a halogen atom, an alkyl group or an alkoxyl group, is let generate chemiluminescence by means of an activator selected from the group consisting of a base, an acid, a salt, a fluorine compound, an enzyme, a catalyst and an amine compound, a cationic surfactant and a fluorescent material are made to coexist.

Abstract: Methods and compositions are described for analyzing complex protein mixtures using fluorescent activity-based probes. In particular, probes that specifically react with and bind to the active form of one or more target proteins are employed. Fluorescent signals obtained from the labeled active target proteins can be related to the presence or amount of active members of the desired target protein class. The methods and compositions described herein can be used, for example, to provide diagnostic information concerning pathogenic states, in identifying proteins that may act as therapeutic targets, and in drug discovery.

Abstract: A method for the detection or quantitation of an analyte in a biological sample is disclosed. The method comprises the steps of selecting a biological sample suspected of containing a target analyte and binding the target analyte in the sample to a binding partner conjugated to an acridinium compound, wherein the acridinium compound comprises an acridinium nucleus having an electron-donating substituent directly attached to the acridinium nucleus at the C2 position. Chemiluminescent acridinium compounds useful in the method have emission maxima close to or in the near infrared (NIR) region (>590 nm). These chemiluminescent acridinium compounds when used in conjunction with short wavelength-emitting acridinium esters (with emission maxima below 450 nm) can be highly useful labels for the simultaneous detection of multiple target analytes in a single assay.

Abstract: An IgG1 ? monoclonal antibody to the immunosuppressive drug tacrolimus has improved properties. In particular, this monoclonal antibody, designated 1H6, has reduced cross-reactivity to several tacrolimus metabolites. This antibody is suitable for performance of immunoassays such as homogeneous immunoassays to detect or determine the presence or concentration of tacrolimus in samples such as blood samples. The invention further includes derivatives of tacrolimus derivatized at a non-binding portion of the molecule useful in immunizing antibody-producing animals and in producing such monoclonal antibodies, as well as labeled derivatives of tacrolimus useful as tacrolimus analogues in such assays. The invention further includes immunoassay methods for the detection of tacrolimus and test kits useful in performing such immunoassays.

Abstract: The present invention provides a method for reducing undesirable light emission from a sample using at least one photon producing agent and at least one photon reducing agent (e.g. dye-based photon reducing agents). The present invention further provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one collisional quencher. The present invention also provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one quencher, such as an electronic quencher. The present invention also provides a system and method of screening test chemicals in fluorescent assays using photon reducing agents. The present invention also provides compositions, pharmaceutical compositions, and kits for practicing these methods.

Abstract: An object of the present invention is to provide a method for detecting a protein using a nonradioactive label which is prevented to a smaller extent than in the case of the interaction of biotin/(strepto)avidin, and which achieves higher detection sensitivity than that of the detection system using DIG. The present invention provides a method for detecting a target substance, which comprises steps of: (A) allowing a target substance to come into contact with a protein labeled with a compound having a 6-membered ring, so as to carry out a binding reaction; and (B) detecting the protein labeled with the compound having a 6-membered ring, which was bound to the target substance, by using an antibody against the above compound having a 6-membered ring.

Abstract: The invention relates to an optical system for determining the distribution, environment, or activity of fluorescently labeled reporter molecules in cells for the purpose of screening large numbers of compounds for specific biological activity. The invention involves providing cells containing fluorescent reporter molecules in an array of locations and scanning numerous cells in each location with a fluorescent microscope, converting the optical information into digital data, and utilizing the digital data to determine the distribution, environment or activity of the fluorescently labeled reporter molecules in the cells. The array of locations may be an industry standard 96 well or 384 well microtiter plate or a microplate which is a microplate having a cells in a micropaterned array of locations. The invention includes apparatus and computerized method for processing, displaying and storing the data.

Abstract: The present invention concerns biological methods of determination using enzymes from the group of oxidases and using optical indicators from the group of lanthanoid-ligand complexes.

Abstract: A method for selective labeling of phosphate groups in natural and synthetic oligomers and polymers in the presence of chemically related groups such as carboxylic acid groups. The method is specifically applicable to biological oligomers and polymers, including phosphopeptides, phosphoproteins and phospholipids. In a specific embodiment, selective labeling of phosphate groups in proteins and peptides, for example, facilitates separation, isolation and detection of phosphoproteins and phosphopeptides in complex mixtures of proteins. Selective labeling can be employed to selectively introduce phosphate labels at phosphate groups in an oligomer or polymer, e.g., in a peptide or protein. Detection of the presence of the label, is used to detect the presence of the phosphate group in the oligomer or polymer. The method is useful for the detection of phosphoproteins or phosphopeptides.

Abstract: Graphitic nanotubes, which include tubular fullerenes (commonly called “buckytubes”) and fibrils, which are functionalized by chemical substitution, are used as solid supports in electrogenerated chemiluminescence assays. The graphitic nanotubes are chemically modified with functional group biomolecules prior to use in an assay. Association of electrochemiluminescent ruthenium complexes with the functional group biomolecule-modified nanotubes permits detection of molecules including nucleic acids, antigens, enzymes, and enzyme substrates by multiple formats.

Abstract: The present invention relates to 9-substituted adenine derivatives represented by formula (I) wherein W is selected from the group consisting of H, halogen, azido and amino group; X is selected from the group consisting of O, S, N(H), CH2, CH and C; Y is selected from the group consisting of H, hydroxy, C1-4 alkyl, C1-4 alkoxy and halogen; R is selected from the group consisting of H, hydroxymethyl, C1-4 alkyl, and C1-4 alkoxy; R1is selected from the group consisting of O, NH and CH2; R2represents a radical selected from the group consisting of —(CH2)n—S—C(O)—R4 and —(CH2)n—S—S—R4, where n=1-4 and R4is a C1-4-alkyl or aryl group and R4 is optionally substituted with a halogen, amino, N-alkylamino, N, N-dialkylamino or C1-4 alkoxy group and wherein each of the R2radicals may be the same or different; and R3is O or S. The derivatives are useful as prodrugs for inhibiting adenylyl cyclase and lowering 3?:5?-cAMP in cells, thereby inhibiting adenylyl cyclase dependent effects within cells.

Abstract: Molecular chemical and/or biological sensors that exhibit a very high density of sensing functionality and which are applicable to a wide variety of different analytes, and enable rapid, convenient and economical detection of analytes are prepared by reacting a dendritic polymer with a diacetylene reagent wherein the diacetylene functional groups are subsequently intramolecularly polymerized to form segments having alternating conjugated double and triple bonds. Sensory groups that can bind with an analyte are bonded to the acetylene monomer units to form molecular sensors that produce observable and measurable color changes when an analyte binds with the sensory groups.

Abstract: Methods, compositions and kits are disclosed. Enzyme conjugates of Formula I may be employed in assays for the determination of an amphetamine and/or a methamphetamine. Immunogenic conjugates of Formula I may be employed to prepare antibodies for an amphetamine and/or for a methamphetamine for use in assays for the determination of an amphetamine and/or a methamphetamine. The enzyme conjugates may also be employed to screen antibodies for use in such methods.

Abstract: The present invention relates to a method for monitoring the effect of in vivo administration of Cathepsin S inhibitors by measuring accumulation of an intermediate degradation product of invariant chain (Ii), in particular the p10 Ii fragment, in blood of dosed subjects.

Abstract: The present invention relates to the use of fluorogenic or chromogenic dyes as reporter molecules for detecting cell entry by a specific molecule.

Abstract: Methods, compositions and kits are disclosed. The compositions are light emitting and comprise a polymeric matrix having dissolved therein a photoactive compound. The composition has the characteristic that, after activation of the photoactive compound, the rate of decrease in the intensity of light emission at any time during a 20-fold decrease in the intensity is proportional to the intensity of the light emission. In one embodiment the polymeric matrix is comprised of particles of about 20 nm to about 100 ?m in diameter to which is bound a specific binding pair member. The particles generally comprise a polymeric matrix having dissolved therein about 1 to about 20% by weight of a dopant. The compositions may be used in methods for determining an analyte. A combination is provided comprising (1) a medium suspected of containing the analyte, (2) and the aforementioned composition. The photoactive substance is activated and the effect of the activating on the optical properties of the combination is detected.

Abstract: The invention relates to a method for monitoring interactions to a target biomolecule comprising the steps of: providing a biomolecule of interest having specificity for the target biomolecule; binding the biomolecule of interest to at least one type of linker molecule comprising a unique mass marker part; introducing the biomolecule of interest to a cell; binding the linker to the target biomolecule; cleaving the linker molecule, thereby leaving the photoactivatable part and the mass marker part bound to the target; analysing the target biomolecule, thereby detecting the unique mass marker part. The detection can be carried out by MS in a parent ion scanning mode, thereby allowing study of the interaction between the biomolecule of interest and the target biomolecule.

Abstract: Methods, compositions and kits are disclosed. Enzyme conjugates of Formula I are employed in assays for the determination of an methylenedioxyamphetamine, a methylene-dioxyethamphetamine, and/or a methylenedioxymethamphetamine. Immunogenic conjugates of Formula I are employed to prepare antibodies for an methylenedioxyamphetamine, a methylenedioxyethamphetamine, and/or for a methylene-dioxymethamphetamine for use in assays for the determination of an methylenedioxyamphetamine, a methylenedioxyethamphetamine, and/or a methylene-dioxymethamphetamine. The enzyme conjugates may also be employed to screen antibodies for use in such methods.

Abstract: The invention relates to assays for measuring ubiquitin ligase activity and for identifying modulators of ubiquitin ligase enzymes.

Abstract: The present invention provides an assay for detection of serum antibodies to M. paratuberculosis. A tracer, comprising a carbohydrate antigen isolated from M. paratuberculosis that is conjugated to a fluorophore, is added to a serum sample from an animal to form a mixture. The fluorescence polarization of the mixture is then measured. The presence of serum antibodies to M. paratuberculosis is indicated by a fluorescence polarization value of the mixture that is higher than the fluorescence polarization value of a control. The present invention further provides a tracer for use in a fluorescence polarization assay for antibodies specific for M. paratuberculosis. The tracer comprises a carbohydrate antigen isolated from M. paratuberculosis and conjugated to a fluorophore, such that the tracer is able to bind to antibodies specific for M. paratuberculosis to produce a detectable change in fluorescence polarization.

Abstract: The present invention provides luminescent lanthanide metal chelates comprising a metal ion of the lanthanide series and a complexing agent comprising at least one salicylamidyl moiety. Also provided are probes incorporating the salicylamidyl ligands of the invention and methods utilizing the ligands of the invention and probes comprising the ligands of the invention.

Abstract: A sensor for the detection of tetrameric multivalent neuraminidase within a sample is disclosed, where a positive detection indicates the presence of a target virus within the sample. Also disclosed is a trifunctional composition of matter including a trifunctional linker moiety with groups bonded thereto including (a) an alkyl chain adapted for attachment to a substrate, (b) a fluorescent moiety capable of generating a fluorescent signal, and (c) a recognition moiety having a spacer group of a defined length thereon, the recognition moiety capable of binding with tetrameric multivalent neuraminidase.

Abstract: A light emitting method of an acridinium ester, comprising reacting said acridinium ester and a superoxide anion, and a method of detecting a substance to be examined, comprising detecting a light emitted by reacting a superoxide anion with an acridinium ester used as a label am described. It is possible to carry out the reaction not under strongly alkaline conditions but around the neutral point and to generate strong luminescence which is stable over a long period of time.