Abstract: Protein kinase A reporters useful for obtaining measurements of protein kinase A activity with high spatial and temporal resolution can be used in high throughput assays to identify potentially therapeutic compounds.

Abstract: The invention relates to the use a BD16 and/or BB18 anti-CD100 antibody or of a chimeric or humanized or human form thereof, or a fragment thereof, for the therapy or diagnosis of a central nervous system disorder, more particularly a myelin disorder or a disease that affects oligodendrocytes, such as multiple sclerosis or HTLV-1 associated myelopathy or peripheral myelinating cells.

Abstract: The present invention provides clostridial toxin substrates useful in assaying for the protease activity of any clostridial toxin, including botulinum toxins of all serotypes as well as tetanus toxins. A clostridial toxin substrate of the invention contains a donor fluorophore; an acceptor having an absorbance spectrum overlapping the emission spectrum of the donor fluorophore; and a clostridial toxin recognition sequence that includes a cleavage site, where the cleavage site intervenes between the donor fluorophore and the acceptor and where, under the appropriate conditions, resonance energy transfer is exhibited between the donor fluorophore and the acceptor.

Abstract: The present invention provides clostridial toxin substrates useful in assaying for the protease activity of any clostridial toxin, including botulinum toxins of all serotypes as well as tetanus toxins. A clostridial toxin substrate of the invention contains a donor fluorophore; an acceptor having an absorbance spectrum overlapping the emission spectrum of the donor fluorophore; and a clostridial toxin recognition sequence that includes a cleavage site, where the cleavage site intervenes between the donor fluorophore and the acceptor and where, under the appropriate conditions, resonance energy transfer is exhibited between the donor fluorophore and the acceptor.

Abstract: Provided is a microfluidic control chip, which includes a filter section having a filter to which anti-immunoglobulin antibodies, which are bound to endogenous antibodies in blood to thereby remove the endogenous antibodies, are immobilized, a first reaction section to which detection antibodies immobilized to fluorescent nano-particles are adsorbed, the detection antibodies being bound to proteins to be detected in blood which is introduced from the filter section with the endogenous antibodies removed therefrom, and a second reaction and detection section including capture antibodies immobilized thereto, binding the capture antibodies to the proteins, which are bound to the detection antibodies introduced from the first reaction section, and detecting a concentration of the proteins based on an intensity of fluorescent light. Thus, the microfluidic control chip can minimize interference of an immune response to maximize the immune response.

Abstract: The present invention provides clostridial toxin substrates useful in assaying for the protease activity of any clostridial toxin, including botulinum toxins of all serotypes as well as tetanus toxins. A clostridial toxin substrate of the invention contains a donor fluorophore; an acceptor having an absorbance spectrum overlapping the emission spectrum of the donor fluorophore; and a clostridial toxin recognition sequence that includes a cleavage site, where the cleavage site intervenes between the donor fluorophore and the acceptor and where, under the appropriate conditions, resonance energy transfer is exhibited between the donor fluorophore and the acceptor.

Abstract: A diagnostic composition to detect antibodies in a sample obtained from an animal or human being infected by Trichinella, comprising at least one peptide containing a series of amino acids that form a continuous or discontinuous epitope recognized by sera from pigs infected with Trichinella.

Abstract: The ionic conjugates include an inorganic particle electrostatically associated with a macromolecule which can interact specifically with predetermined chemical species or biological targets.

Abstract: In accordance with the present invention, it has been discovered that introduction of hydrophilic sulfoalkyl substituents and/or hydrophilic linkers derived from homocysteic acid, cysteic acid, glycine peptides, tetraethylene oxide, and the like, offset the hydrophobicity of the acridinium ring system to produce a more soluble label which can be attached to an antibody at higher loading before precipitation and aggregation problems are encountered. Additional compounds described herein contain linkers derived from short peptides and tetraethylene oxide which increase aqueous solubility due to hydrogen bonding with water molecules. The present invention also embraces reagents for multiple acridinium labeling for signal amplification composed of a peptide bearing several acridinium esters with sulfonate groups at regularly spaced intervals for increased solubility. The invention also embraces assays employing the above-described compounds.

Abstract: A gel microdrop composition is provided. In certain embodiments, the gel microdrop composition contains a polymer matrix, an effector particle that releases an effector molecule into the polymer matrix, a first reporter particle that emits a first optically detectable signal and a second reporter particle that emits a second optically detectable signal that is distinguishable from the first optically detectable signal, where the effector particle and said first and second reporter particles are encapsulated by the polymer matrix. Methods of screening that employ the gel microdrop composition and methods of making the gel microdrop composition are also disclosed.

Abstract: Clostridial toxin substrates comprising a lanthanide donor complex, an acceptor, and a Clostridial toxin recognition sequence including a cleavage site; methods for determining the activity of a Clostridial toxin from a test sample using such Clostridial toxin substrates; cell compositions comprising such Clostridial toxin substrates and a Clostridial toxin receptor; and methods for determining the activity of a Clostridial toxin from a test sample using such cell compositions.

Abstract: The present invention provides clostridial toxin substrates useful in assaying for the protease activity of any clostridial toxin, including botulinum toxins of all serotypes as well as tetanus toxins. A clostridial toxin substrate of the invention contains a donor fluorophore; an acceptor having an absorbance spectrum overlapping the emission spectrum of the donor fluorophore; and a clostridial toxin recognition sequence that includes a cleavage site, where the cleavage site intervenes between the donor fluorophore and the acceptor and where, under the appropriate conditions, resonance energy transfer is exhibited between the donor fluorophore and the acceptor.

Abstract: Small Molecule Metabolite Reporters (SMMRs) for use as in vivo glucose biosensors, sensor compositions, and methods of use, are described. The SMMRs include boronic acid-containing xanthene, coumarin, carbostyril and phenalene-based small molecules which are used for monitoring glucose in vivo, advantageously on the skin.

Abstract: The present invention provides clostridial toxin substrates useful in assaying for the protease activity of any clostridial toxin, including botulinum toxins of all serotypes as well as tetanus toxins. A clostridial toxin substrate of the invention contains a donor fluorophore; an acceptor having an absorbance spectrum overlapping the emission spectrum of the donor fluorophore; and a clostridial toxin recognition sequence that includes a cleavage site, where the cleavage site intervenes between the donor fluorophore and the acceptor and where, under the appropriate conditions, resonance energy transfer is exhibited between the donor fluorophore and the acceptor.

Abstract: The present invention measures defect fluorescence exhibited from a defect level mainly on a semiconductor nanoparticle surface site which has an energy level existing inside the forbidden band of energy levels inside the semiconductor nanoparticle.

Abstract: Fluorescent indicators including a binding protein moiety, a donor fluorescent protein moiety, and an acceptor fluorescent protein moiety are described. The binding protein moiety has an analyte-binding region which binds an analyte and causes the indicator to change conformation upon exposure to the analyte. The donor moiety and the acceptor moiety change position relative to each other when the analyte binds to the analyte-binding region. The donor moiety and the acceptor moiety exhibit fluorescence resonance energy transfer when the donor moiety is excited and the distance between the donor moiety and the acceptor moiety is small. The indicators can be used to measure analyte concentrations in samples, such as calcium ion concentrations in cells.

Abstract: An alloyed semiconductor quantum dot comprising an alloy of at least two semiconductors, wherein the quantum dot has a homogeneous composition and is characterized by a band gap energy that is non-linearly related to the molar ratio of the at least two semiconductors; a series of alloyed semiconductor quantum dots related thereto; a concentration-gradient quantum dot comprising an alloy of a first semiconductor and a second semiconductor, wherein the concentration of the first semiconductor gradually increases from the core of the quantum dot to the surface of the quantum dot and the concentration of the second semiconductor gradually decreases from the core of the quantum dot to the surface of the quantum dot; a series of concentration-gradient quantum dots related thereto; in vitro and in vivo methods of use; and methods of producing the alloyed semiconductor and concentration-gradient quantum dots and the series of quantum dots related thereto.

Abstract: The present invention provides a method of predicting pregnancy outcome in a subject by determining the amount of an early pregnancy associated molecular isoform of hCG in a sample. The present invention further provides a method for determining the amount of early pregnancy associated molecular isoforms of human chorionic gonadotropin (hCG) in a sample. The present invention also provides a diagnostic kit for determining the amount of early pregnancy associated hCG in a sample. The present invention additionally provides an antibody which specifically binds to an early pregnancy associated molecular isoform of human chorionic gonadotropin. Finally, the present invention provides methods for detecting trophoblast or non-trophoblast malignancy in a sample.

Abstract: A fluorescent probe which specifically and efficiently traps nitrogen monoxide, zinc ion etc. to emit fluorescence is provided. A compound represented by the following general formula (I): [wherein R1 and R2 represent hydrogen atom, or a group represented by the following formula (A): (wherein X1 to X4 represent hydrogen atom, an alkyl group, or a protective group for amino group, and m and n represent 0 or 1); R3 and R4 represent hydrogen atom, a C1-6 alkyl group, or a C1-6 alkoxy group; R5 to R12 represent hydrogen atom, sulfo group, phospho group, a halogen atom, or a C1-6 alkyl group; R13 and R14 represent a C1-18 alkyl group; Z1 represents oxygen atom, sulfur atom, or —N(R15)— (wherein R15 represents hydrogen atom, or a C1-6 alkyl group); Y1 and Y2 represent —C(?O)—, —C(?S)—, or —C(R16)(R17) (wherein R16 and R17 represent a C1-6 alkyl group); and M? represents a counter ion in a number required for neutralizing the charge].

Abstract: Methods, compositions and kits are provided for assessing angiogenesis through sensitive, direct detection of activation of endothelial cells at molecular levels. In general, activation of endothelial cells is detected by measuring the levels of cellular components and their protein complexes participating in a specific angiogenesis signaling pathway in endothelial cells. The methods can be used for assessing status of diseases associated with undesirable angiogenesis, such as the likelihood of developing the disease, presence or absence of the disease, prognosis of the disease and the likelihood of response or resistance to a particular anti-angiogenic therapy. The methods can also be used to guide the design of effective therapeutic regimens targeting a specific angiogenic signaling pathway, as well as in conjunction with therapeutic intervention of diseases or conditions associated with undesirable angiogenesis.

Abstract: The present invention provides an approach for the simultaneous determination of the activation states of a plurality of proteins in single cells. This approach permits the rapid detection of heterogeneity in a complex cell population based on activation states, and the identification of cellular subsets that exhibit correlated changes in activation within the cell population. Moreover, this approach allows the correlation of cellular activities or properties. In addition, the use of potentiators of cellular activation allows for characterization of such pathways and cell populations.

Abstract: Clinical samples can be analyzed using microparticles to determine the serodiagnosis of a viral infection from two candidate viral infections of the same viral group. Serodiagnosis can be determined via a pooled population of subsets of microparticles, with the particles in the pooled population having a bound viral group-reactive antibody and the particles in each subset having at least one characteristic classification parameter that distinguishes between subsets. Viral antigens of antibodies of interest in the same viral-class as the viral group-reactive antibody can be bound to the viral group-reactive antibody on the microparticles, and subsequently exposed to a clinical sample. Binding and labeling can be used. Automated analysis of data from multiplexed flow analysis can determine the presence or absence of antibodies of interest in the sample, thereby diagnosing for two candidate viral infections in a single assay.

Abstract: The present invention relates to methods and kits for detecting an analyte in a test sample using acridinium-9-carboxylate aryl esters.

Abstract: Disclosed are methods for detecting antibody in a sample, where the antibody targets an antigen expressed by red blood cells or red blood cell ghosts. Rather than detecting the binding events between a particular antigen antibody pair (as in traditional agglutination based assays) the methods herein allow for multiplexed detection of clinically important allo-immune antibodies to blood group antigens. Specifically the method involves generating fluorescently encoded red blood cells or red blood cell ghosts with known antigen presentation and using them to detect the presence of antibody in serum/plasma with a fluorescent sandwich type immunoassay. The assay results can be read using flow cytometric or fluorescent microscope based imaging techniques.

Abstract: Chemiluminescent substrate delivery systems comprising a conjugate a dendrimer and at least one chemiluminescent substrate are provided. The substrate delivery systems can also include a chemiluminescence enhancer. The dendrimer/chemiluminescent substrate conjugates can be used in kits including an enzyme capable of activating the chemiluminescent substrate to produce a peroxygenated intermediate that decomposes to produce light. The dendrimer/chemiluminescent substrate conjugates can be used in assays to detect the presence of an analyte (e.g., an enzyme, an antibody, an antigen or a nucleic acid) in a sample.

Abstract: Chemiluminescent acridinium compounds are used in homogeneous assays to determine the concentration of an analyte in a sample without strong acid or strong base treatment. The chemiluminescent acridinium compounds include acridinium esters with electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus to inhibit pseudo-base formation, or acridinium sulfonamides with or without electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus.

Abstract: A fluorescent labeling reagent of the present invention includes an inorganic fluorescent particle and a material (A) having a material (B) of biological origin adsorbed or bound thereto. The inorganic fluorescent particle is integrated with the material (A) so as to form the reagent of the present invention. The inorganic fluorescent particle used in the present invention is capable of emitting light with a wavelength of 650 nm to 1600 nm in the infrared region or the near-infrared region which can be detected by means of Si—CCD or InGaAs—PD and can penetrate an H2O rich sample when excited by light with a wavelength of 650 nm or longer which has the shortest transparent wavelength of AlInGaP-LD including oxygen adsorption type hemoglobin used for DVDs etc.

Abstract: A method for photochemical reactor characterization includes an application of using dyed microspheres exposed to UV irradiation under a collimated-beam system. Particle specific fluorescence intensity measurements are conducted using samples form the collimated beam and flow-through reactor results using flow cytometry. A numerical model may be used to simulate the behavior of the reactor system to provide a particle-tracking algorithm to interrogate the flow and intensity field simulations for purposes of developing a particle specific estimate of the dose delivery. A method for measuring UV dose distribution delivery in photochemical reactors is provided that includes introducing microspheres labeled with a photochemically-active compound in a UV reactor. The labeled microspheres are harvested downstream of the irradiated zone of a UV reactor and exposed to UV irradiation under a collimated beam of UV irradiation.

Abstract: In accordance with the present invention, it has been discovered that introduction of hydrophilic sulfoalkyl substituents and/or hydrophilic linkers derived from homocysteic acid, cysteic acid, glycine peptides, tetraethylene oxide, and the like, offset the hydrophobicity of the acridinium ring system to produce a more soluble label which can be attached to an antibody at higher loading before precipitation and aggregation problems are encountered. Additional compounds described herein contain linkers derived from short peptides and tetraethylene oxide which increase aqueous solubility due to hydrogen bonding with water molecules. The present invention also embraces reagents for multiple acridinium labeling for signal amplification composed of a peptide bearing several acridinium esters with sulfonate groups at regularly spaced intervals for increased solubility. The invention also embraces assays employing the above-described compounds.

Abstract: This invention is directed to a method for preparation of a biological sample for measurement of protein epitopes that allows for the preservation of intracellular protein epitopes and detection of signal transduction pathways based on the ability to capture transient activation states of the epitopes. The method provided by the invention allows for the rapid fixation of biological samples containing red blood cells, to ensure that epitopes of signal transduction molecules and other intracellular protein epitopes are preserved in the active state. The method of the invention further allows for lysis of red blood cells, thereby making it a useful method for cytometric analysis of biological samples, including, for example, whole blood, bone marrow aspirates, peritoneal fluids, and other red blood cell containing samples. The invention also provides a method to recover or “unmask” epitopes on intracellular antigens that have been made inaccessible by the cross linking fixative necessary to fix the sample.

Abstract: The present invention relates to a fluorescent label characterized by containing a hydrophilic polymer having an anionic group, a polyether derivative, and a phosphor, in which the phosphor is bound to the hydrophilic polymer via the polyether derivative, and also relates to a fluorescently labeled recognition substance labeled with the fluorescent label, and an immunoassay method using the recognition substance.

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: The present invention relates to hydrophilic, high quantum yield acridinium compounds. It has been discovered that the placement of electron-donating groups in the acridinium ring system increases the amount of light that is emitted by the corresponding acridinium compound when its chemiluminescence is triggered by alkaline peroxide. More specifically, it has been found that the placement of one or two hydrophilic, alkoxy groups at the C-2 and/or C-7 position of the acridinium ring system of acridinium compounds increases their quantum yield and enhances the aqueous solubility of these compounds. The present hydrophilic, high quantum yield, acridinium compounds are useful chemiluminescent labels for improving the sensitivity of immunoassays.

Abstract: New chemiluminescent compounds, stable in aqueous buffers, for use in biological assaying include acridanebased compounds and (1,2)-dioxetanes. Among the new acridanebased compounds are water-soluble acridanes, enhancer coupled acridanes, bis and trisacridanes as well as acridane-(1,2)-dioxetanes. Among the new (1,2)-dioxetanes are electron deficient group-containing dioxetanes and tethered bis-1,2-dioxetanes. The (1,2)-dioxetanes are useful as substrates for various enzymes. The acridanes can be admixed with an oxidizing agent. An aqueous buffer and, optionally, a stabilizer to form a substrate or reagent formulation useful for assaying, inter alia, HRP.

Abstract: Arrays of microparticle populations, each population labeled with a single fluorescent dye, are provided for use in multiplex assays. The populations form a virtual multidimensional array wherein each microparticle is identified by fluorescence intensity in two different fluorescence detection channels. The arrays are useful in a variety of assays, including multiplex, multi-analyte assays for the simultaneous detection of two or more analytes by, for example, flow cytometry, and a labeling reagents in, for example, microscopy. The use of singly-dyed microparticles to form multidimensional arrays greatly simplifies the creation of multiplex assays.

Abstract: The present invention is directed to a novel method for quantifying antigen, such as the amount expressed on a cell. The method comprises formulating an equation of correlation between the amount expressed of expressed antigen and the intensity of fluorescence from fluorescent labelled antibody.

Abstract: Methods using chemiluminescent label compounds and chemiluminescent labeled conjugates are provided. The compounds comprise an acridan ring bearing an exocyclic ketene dithioacetal group and further contain a labeling substituent which permits attachment to compounds of interest. The novel chemiluminescent compounds and labeled conjugates are convenient to prepare, are highly stable, and generate chemiluminescence rapidly on demand. The compounds and conjugates are useful in assays of an analyte in a sample and in assays employing labeled specific binding pairs.

Abstract: A separation free bioanalytical assay method for measuring an analyte from a biological fluid or suspension containing microparticles as a bioaffinity binding solid phase, a biospecific secondary reagent labelled with a two-photon fluorescent dipyrrometheneboron difluoride dye of specified structure, focusing the laser into the reaction suspension, and measuring two-photon excited fluorescence from single microparticles when they randomly float or are guided by the radiation pressure of the excitation laser through the focal volume of the laser beam.

Abstract: Methods of detecting and/or quantifying an IgE antibody present in a liquid sample. The IgE antibody is specific to a ligand in the form of an antigen, an antibody, or a hapten. These methods can be used for monitoring and evaluating the immunological status of a subject.

Abstract: Asymmetrically branched polymers are combined with bioactive agents for a variety of purposes including drug delivery and conjugation to one member of a binding pair for use in an assay.

Abstract: Methods using chemiluminescent label compounds and chemiluminescent labeled conjugates are provided. The compounds comprise an acridan ring bearing an exocyclic ketene dithioacetal group and further contain a labeling substituent which permits attachment to compounds of interest. The novel chemiluminescent compounds and labeled conjugates are convenient to prepare, are highly stable, and generate chemiluminescence rapidly on demand. The compounds and conjugates are useful in assays of an analyte in a sample and in assays employing labeled specific binding pairs.

Abstract: The present invention relates to luminescent compounds having a functionalised linker arm, their synthesis and use in bioconjugation and labelling of biomolecules, such as for example nucleosides, nucleotides, nucleic acids (DNA, RNA or PNA) and proteins, as well as their use in the execution of in vitro and in vivo analytic and diagnostic assays.

Abstract: Assays for detecting molecular modifications such as phosphate modifications and the presence and/or activity of enzymes and other agents involved in facilitating or otherwise regulating such modifications.

Abstract: The present invention provides methods and systems for performing in vivo flow cytometry. In one embodiments, selected circulating cells of interest of a subject are labeled with fluorescent probe molecules. The labeled cells are irradiated in-vivo so as to excite the fluorescent probes, and the radiation emitted by the excited probes is detected, preferably confocally. The detected radiation is then analyzed to derive desired information, such as relative cell count, of the cells of interest. In some embodiments, the circulating cells comprise apoptotic cells whose detection can allow, e.g., non-invasive monitoring of the efficacy of a cancer treatment, such as an anti-tumor or an anti-angiogenic therapy.

Abstract: Compounds having the general of formula I and/or formula II wherein R1 and R2 are the same or different and are independently selected from the group consisting of —H, —C1-C18-alkyl or -?-sulfoalkyl; X and Y are the same or different and are independently selected from the group consisting of —O?, —OH, —SH, —NH—NH2, —F, —Cl, —Br, —I, —O-Su (succinimidyl/sulfosuccinimidyl), —O-STP (4-sulfo-2,3,5,6-tetrafluorophenyl), —O-TFP (2,3,5,6-tetrafluorophenyl), —O-benzotriazole, -benzotriazole, —NR—CO—CH2—I, —NR2, —NR-biomolecule, —NR-L-COO?, —NR-L-COOH, —NR-L-COO-Su, —NR-L-COO-STP, —NR-L-COO-TFP, —NR-L-CONR2, —NR-L-CO-biomolecule, —NR-L-CO—NH—NH2, —NR-L-OH, —NR-L-O-phosphoramidite, —NR-L-CHO, —NR-L-maleimid, or —NR-L-NH—CO—CH2—I; where R is equal to R1 and R2 and L is selected from the group consisting of a divalent linear (—(CH2)o—, o=1 to 15), crossed, or cyclic alkane group that can be substituted by at least one atom selected from the group consisting of oxygen, substituted ni

Abstract: The present invention describes a bioconjugation strategy and compounds that are useful therein in which a fluorescent signal is produced when two molecular or supramolecular entities are linked by chemoselective combination of one linker having an azido or halide substituent group with another linker having a cyano or an alkyne substituent group. A kit is also provided.

Abstract: Provided are compounds capable of covalently binding to a protein tyrosine phosphatase (PTP). The compounds comprise Formula A: Also provided are compositions comprising one of the above compounds covalently bound to a member of the PTP superfamily, methods of labeling a PTP using the compounds, methods of isolating a PTP from a mixture of proteins using the compounds, methods of evaluating whether a substance is an inhibitor of a PTP using the compounds, methods of evaluating the specificity of an inhibitor of a PTP using the compounds, methods of identifying a PTP involved in a disease in a mammal using the compounds, and methods of diagnosing a disease in a mammal using the compounds.

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: Fluorogenic or chromogenic dyes are useful as reporter molecules for detecting cell entry by a specific molecule.

Abstract: Methods and compound useful for detecting a source of hydrogen peroxide are disclosed wherein a signalling compound of the formula: is reacted with peroxide. Sig is a non-polymeric organic group, B is a boron atom, and each R is independently selected from hydrogen, alkyl and aryl groups and can be joined together as a straight or branched alkylene chain forming a ring or as an aromatic ring. A detectable product compound of the formula Sig-OH or Sig-O? is produced and detected by measuring color, absorbance, fluorescence, chemiluminescence, or bioluminescence. The signalling compound itself does not possess the detectable property or does so only to a very weak degree. The methods can be used as a detectable signal in assays for peroxide or peroxide-producing enzymes and in assays employing enzyme-labeled specific binding pairs.