Abstract: The invention is directed to a system and method for detecting substances, such as explosives and/or drugs, using, in part, short bursts of energy light from a relatively low energy strobe. Embodiments include coupling the strobe with a detector for use in a portable hand-held unit, or a unit capable of being carried as a backpack. Embodiments further include placement of one or more stroboscopic desorption units and detectors in luggage conveyors systems, carry-on X-ray machines, and check-in counter locations. Embodiments further comprise the use of a strobe or another energy source to assist in maintaining the integrity of a SERS substrate surface operatively associated with the detector system, wherein the SERS substrate may be positioned in hand wand spaced apart from at least a portion of the detector. In another embodiment, the Raman excitation source may be located directly in the hand wand of a portable stroboscopic detection system.

Abstract: The present invention relates to methods and kits for diagnosing, ascertaining the clinical course of myelodysplastic syndrome (MDS) and ascertaining response to a therapy regimen of myelodysplastic syndrome. Specifically the invention provides methods and kits useful in the diagnosis and determination of clinical parameters associated with MDS based on surface markers unique to MDS.

Abstract: Novel conjugates of nanoparticles are provided and have particular utility in the detection of latent fingerprints by their ability to bind to a fingerprint residue. The conjugate comprises a nanoparticle attached to a linker group having a terminal reactive moiety, wherein said nanoparticle comprises a core of a first semiconductor material having a first luminescence and a shell of a second material which at least partially surrounds the core. The conjugated nanoparticle can bind to the fingerprint residue and can be detected using fluorescence.

Abstract: Novel fluorescent dye comprising metal oxide nanoparticles are prepared where the nanoparticles are as small as 3 nm or up to 7000 nm in diameter and where the dye is bound within the metal oxide matrix. In some embodiments the invention, novel dyes are covalently attached to the matrix and in other embodiments of the invention a dye is coordinate or ionic bound within the metal oxide matrix. A method for preparing the novel covalently bondable modified fluorescent dyes is presented. A method to prepare silica comprising nanoparticles that are 3 to 8 nm in diameter is presented. In some embodiments, the fluorescent dye comprising metal oxide nanoparticles are further decorated with functionality for use as multimodal in vitro or in vivo imaging agents. In other embodiments of the invention, the fluorescent dye comprising metal oxide nanoparticles provide therapeutic activity and incorporated therapeutic temperature monitoring.

Abstract: A nanostructured particulate material, which includes a redox active luminescent organic and/or ionic compound, is provided herein. The nanostructured particulate material may be used for determining the presence of an analyte of interest in a sample by detecting the emitted electromagnetic radiation generated by exposing a reagent mixture, which includes the nanostructured material and the target analyte, to chemical or electrochemical energy.

Abstract: The present invention describes the development of a end-capped bipyridine compound having formula A and the zinc complex having formula B. The assay having formula 1 can be used to estimate and quantify the amount of zinc ions by monitoring the fluorescence changes. The assay with formula 1 can be use to image and detect Zn2+ ions in MCF7 cell lines. The zinc complex of formula 2 and 4 can be used as a fluorescent sensor for cyanide anions using analyte replacement protocol. The assay with formula 2 is selective only to cyanide anions even in the presence of other competing anions. The assay with formula 3 having bright green solid state emission is used for the preparation of formula 4. The orange fluorescent powder of assay with formula 4 is used for the selective detection of CN? ions in aqueous solution.

Abstract: In order to investigate a specimen (30) with the aid of a microscope (20), dye particles (40, 42) in the specimen (30) are excited to fluoresce with the aid of a first illumination light beam (24). Fluorescent light proceeding from the specimen (30) is directed via an optical arrangement (34) onto an areal sensor (36), the optical arrangement (34) acting on the fluorescent light in such a way that sub-beams of the fluorescent light interfere with themselves, so that interference patterns produced as a result of the interference are imaged on a sensitive surface of the areal sensor (36) and sensed thereby. Positions of the dye particles (40, 42) within the specimen (30) are ascertained as a function of the interference patterns.

Abstract: A centrifugal force-based microfluidic device for a multiplexed analysis and an analyzing method using the same are provided. The microfluidic device includes a platform and a microfluidic structure including a plurality of chambers formed within the platform, and valves positioned between the chambers. The microfluidic structure includes a sample separation chamber connected to a sample injection hole, and a plurality of reaction chambers accommodating two or more types of markers specifically reacting with different types of target materials, separately by type. At least one of the target materials is a standard material, and at least one of the markers is a standard marker specifically reacting with the standard material.

Abstract: This invention provides polymeric coordination compounds capable of forming three-dimensional microporous metal organic frameworks (MMOFs) that are useful for detection of explosive compounds. The polymeric coordination compounds comprise a repeating unit comprising a transition metal coordinated to at least one binding member of a bidentate binding site on each of two polyfunctional ligands and one binding site of a bis-pyridine exodentate bridging ligand, for example, the repeating unit comprising formula [Zn2(bpdc)2(bpee)] (bpdc=4,4?-biphenyldicarboxylate; bpee=1,2-bipyridylethene). Methods of preparing such polymeric coordination compounds, methods of using them for detection of explosive compounds, and sensors or sensor arrays comprising such polymeric coordination compounds for detection of explosive compounds, especially those comprising one or more nitro (—NO2) groups, are also disclosed.

Abstract: A calibration system characterizes luminescence measurement systems, in particular spectrally resolving, wide-field and/or confocal imaging systems. The calibration system has a baseplate with at least one flow-through channel, wherein the at least one channel is formed as a sample chamber for the luminescence measurement system, at least one reservoir in communication with the at least one channel and adapted to receive a liquid, and at least one focusing device integrated into a baseplate for setting a defined measurement beam focus of the luminescence measurement system to be calibrated by using a focusing surface.

Abstract: The invention relates to a method for suppressing the FRET emitted by a reaction medium containing a pair of fluorescent FRET partner conjugates specific for a biological event, characterized in that a FRET signal killer which does not disturb said biological event is introduced into this medium.

Abstract: A selective, fluorescent “turn-on” probe and method for the detection of ozone in biological and atmospheric samples, wherein the method of detecting ozone in a sample comprises the steps of (1) contacting the sample with a fluorophore capable of undergoing allylic ether or allylic ester cleavage and (2) detecting fluorescence in the sample.

Abstract: A cell sorting device using an inexpensive chip capable of being exchanged for each sample. The chip includes: a first flow path allowing buffer fluid containing cells to flow down; second and third flow paths which put the first flow path therebetween and allow buffer fluid not containing cells to flow down; a fourth flow path which allows the buffer fluid as a single flow path formed by joining the buffer fluids in the other three flow paths; a cell detecting region for detecting cells flowing with the buffer fluid down the fourth flow path; and a cell sorting region for sorting the cells according to a type of the cells detected. The first to fourth flow paths are cascaded, are supplied with the buffer fluid from reservoirs with the same fluid level, and have substantially the same width or cross-section area.

Abstract: In an embodiment, there is disclosed an inspection method for detecting the presence of imprintable medium on an imprint lithography template. The method includes contacting the imprint lithography template with a marker, the marker being attachable to imprintable medium that may be on the imprint lithography template, the marker being configured to interact with incident radiation when attached to the imprintable medium, directing radiation at the imprint lithography template, and measuring radiation re-directed by the imprint lithography template to attempt to detect presence of a marker that has attached to the imprintable medium, from the interaction of the marker with the incident radiation, and thus detect the presence of imprintable medium to which the marker is attached.

Abstract: An approach is provided in detecting plated-through hole defects in printed circuit boards (PCBs). The printed circuit board is exposed to a modified-silane solution. The modified-silane solution has a luminescent moiety and the modified-silane solution binds to exposed glass within a glass fiber layer of the printed circuit board. Plated-through hole defects are identified in the printed circuit board by detecting a luminescence at a surface location of the printed circuit board. Each surface location where the luminescence is detected corresponds to one of the plated-through hole defects.

Abstract: Devices and methods for extraction, identification, authentication, and quantification of one or more covert markers in a material are disclosed. An extraction system includes a first plug flow mixer for mixing a first fluid bearing a marker and transfer agent into a plug flow. The mixing and flowing of the immiscible liquids causes transfer of the marker from the fluid to the transfer agent. A splitter having filters of different surface energies separates the two immiscible liquids, the transfer agent bearing the marker. A second plug flow can be used to transfer the marker to a second transfer agent. The transferred marker is detected to authenticate the original fluid. The marker can be further isolated, activated, or reacted to perform detection, identification or authentication. With the device, a number of independent processing and analytic steps are combined onto a single, portable unit.

Abstract: Methods and compositions are provided that include a multichromophore and/or multichromophore complex for identifying a target biomolecule. A sensor biomolecule, for example, an antibody can be covalently linked to the multichromophore. Additionally, a signaling chromophore can be covalently linked to the multichromophore. The arrangement is such that the signaling chromophore is capable of receiving energy from the multichromophore upon excitation of the multichromophore. Since the sensor biomolecule is capable of interacting with the target biomolecule, the multichromophore and/or multichromophore complex can provide enhanced detection signals for a target biomolecule.

Abstract: The present invention provides an inspection chip using light, which is able to provide an irradiation of light at a high precision. The present invention further provides an inspection chip capable of carrying out the inspection of a sample in a simple manner by using a plurality of lights. The inspection chip of the present invention comprises a light amplifier element and a sample holding section for holding a sample, in which the light amplifier element is oriented so as to face to the sample holding section, so that the light emitted from the light amplifier element can irradiate the sample held in the sample holding section.

Abstract: In one non-limiting aspect, sterilizable reagent materials for diagnostic elements are provided. In other aspects, sterilized diagnostic elements and techniques for the production of the same are disclosed. In one embodiment, a sterilized diagnostic element includes a chemical detection reagent including at least one component that is sensitive to ionizing radiation. The sterilized diagnostic element is also mediator-free and the at least one component sensitive to ionizing radiation is present in a functional form in a proportion of ? 80% based on the total amount of the respective component in the diagnostic element before sterilization. In certain aspects, the at least one component sensitive to ionizing radiation includes one or both of an enzyme and a coenzyme. Other aspects include, but are not limited to, unique methods, techniques, products, systems and devices involving sterilizable reagent materials or sterilized diagnostic elements.

Abstract: A vapochromic gold-copper complex [AuL2(Cu(Y)n)2](X)3 exhibiting luminescence is provided, where L is an N-heterocyclic carbene; Y is a heteroatom-containing ligand; X is an anion, and n is an integer having a value of 1 or 2, and solvates thereof. A reaction of [AuL2(Cu(Y)n)2](X)3 with water vapor or an organic compound vapor, for example, affords a modified complex that yields a change in luminescence color under UV excitation. These tricationic vapochromic materials exhibit large changes in the emission through ligand substitution reactions between the solid complex and vapors, which permit use in luminescent vapochromic sensors.

Abstract: A homogeneous immunoassay method and system for quantitative determination of total immunoglobulin E and specific antibody levels to a plurality of allergens, in which a relatively small sampling of blood is required. The method utilizes relatively small microparticles in aqueous suspension. The immunoassay procedure is an immunometric sandwich procedure preferably utilizing biotin-streptavidin signal amplification techniques and R-phycoerytherin fluorescent labels.

Abstract: A method for assaying a sample for each of multiple analysis is described. The method includes contacting an array of spaced-apart test zones with a liquid sample (e.g., whole blood). The test zones are disposed within a channel of a microfluidic device. The channel is defined by at least one flexible wall and a second wall which may or may not be flexible. Each test zone includes a probe compound specific for a respective target analyte. The microfluidic device is compressed to reduce the thickness of the channel, which is the distance between the inner surfaces of the walls within the channel. The presence of each analyte is determined by optically detecting an interaction at each of multiple zones for which the distance between the inner surfaces at the corresponding location is reduced. The interaction at each test zone is indicative of the presence in the sample of a target analyte.

Abstract: A microfluidic device with microstructure includes a channel for accommodating an electrolytic solution therein and at least one microstructure formed in the channel. When an alternating-current signal is input to the microfluidic device so that a surface of the microstructure is polarized by a generated electric field, ions having polarity reverse to that of an electrolytic solution will migrate to the surface of the microstructure to form a field-induced electrical double layer to result in electro-osmotic flows at the corners at two sides of the microstructure, which causes formation of relatively fierce circular vortices in the solution. A sensing system and a sensing method using the microfluidic device with microstructure are also disclosed.

Abstract: A test module for concentrating pathogens in a biological sample, the test module having an outer casing with a receptacle for receiving the sample, a dialysis device in fluid communication with the receptacle and configured to separate the pathogens from other constituents in the sample, and, a lab-on-a-chip (LOC) device being in fluid communication with the dialysis device and configured to analyze the pathogens.

Abstract: The present invention relates to the use of luminescent Ir(III) and Ru(II) complexes and their application in electro-chemiluminescence and bio-labelling. The use refers to the labelling and detection of biomolecules.

Abstract: The disclosure provides microstructured articles and methods useful for detecting an analyte in a sample. The articles include microwell arrays.

Abstract: Disclosed are methods for conducting assays of samples, such as whole blood, that may contain cells or other particulate matter. Also disclosed are systems, devices, equipment, kits and reagents for use in such methods. One advantage of certain disclosed methods and systems is the ability to rapidly measure the concentration of an analyte of interest in blood plasma from a whole blood sample without blood separation and hematocrit correction.

Abstract: The invention encompasses microfluidic microarray assemblies (MMA) and subassemblies and methods for their manufacture and use. In one embodiment, first and second channel plates are provided and are sealingly connected to a test chip in consecutive steps. Each plate includes microfluidic channels configured in a predetermined reagent distribution pattern. The test chip comprises a plurality of discrete test positions, each test position being located at the intersection between a first predetermined reagent pattern and a second predetermined reagent pattern, wherein at least one of said patterns is non-linear. The first channel plate allows the distribution of a first reagent on said test chip, wherein said first reagent is immobilized at said test positions. The second channel plate allows the distribution of a second reagent on said test chip, wherein said second reagent comprises a plurality of different test samples.

Abstract: The present invention provides a novel class of macrocyclic compounds as well as complexes formed between a metal (e.g., lanthanide) ion and the compounds of the invention. Preferred complexes exhibit high stability as well as high quantum yields of lanthanide ion luminescence in aqueous media without the need for secondary activating agents. Preferred compounds incorporate hydroxy-isophthalamide moieties within their macrocyclic structure and are characterized by surprisingly low, non-specific binding to a variety of polypeptides such as antibodies and proteins as well as high kinetic stability. These characteristics distinguish them from known, open-structured ligands.

Abstract: The present invention provides microfabricated substrates and methods of conducting reactions within these substrates. The reactions occur in plugs transported in the flow of a carrier-fluid.

Abstract: The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the coumarin unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal synthetases, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine and related translation systems.

Abstract: The invention relates to processes and devices for detecting an analyte in a sample by fluorescence measurement of a fluorophore, wherein the detection medium which contains a fluorophore or a precursor of the fluorophore is admixed with an absorber whose absorbance spectrum superimposes the fluorescence excitation range of the fluorophore. The system consisting of the fluorophore and the absorber, which is produced in the detection medium, has an altered effective fluorescence excitation range with an altered fluorescence excitation maximum. Illumination with fluorescence excitation light can take place within the range of this altered excitation maximum. The measured signal obtained from determining fluorescence emission exhibits only low dependence on the wavelength of the excitation light.

Abstract: Disclosed are compositions and methods for using label free optical biosensors for performing cell assays. In certain embodiments the assays can be performed in highthough put methods and can be multiplexed.

Abstract: Disclosed are a solvatochromic functional monomer having the chemical structure and a process for preparing the same. The solvatochromic functional monomer can be used for fabrication of molecularly imprinted polymer based (MIP-based) solvatochromic chemosensors. This involves the incorporation of the solvatochromic functional monomer as reporter into the molecularly imprinted polymer. The solvatochromic functional monomers as reporters signal the analyte-to-receptor displacing event within the receptor sites without the need for intermolecular interaction between the analyte and the receptor.

Abstract: Methods and devices are provided for the trapping, including optical trapping; analysis; and selective manipulation of particles on an optical array. A device parcels a light source into many points of light transmitted through a microlens optical array and an Offner relay to an objective, where particles may be trapped. Preferably the individual points of light are individually controllable through a light controlling device. Optical properties of the particles may be determined by interrogation with light focused through the optical array. The particles may be manipulated by immobilizing or releasing specific particles, separating types of particles, etc.

Abstract: A microfluidic device for generation of monodisperse droplets and initiating a chemical reaction is provided. The microfluidic device includes a first input microchannel having a first dimension and including a first phase located therein. The device also includes a second input microchannel having a second dimension and including a second phase located therein. In accordance with the present disclosure, the second dimension is different from the first dimension and the first phase is immiscible in the second phase. A microchannel junction is also present and is in communication with the first input microchannel and the second input microchannel. The device further includes an output channel in communication with the microchannel junction and set to receive a monodisperse droplet. In the present disclosure, the difference in the first dimension and the second dimension creates an interfacial tension induced force at the microchannel junction which forms the monodisperse droplet.

Abstract: Provided are nucleic acid compositions modified with intercalating aromatic compounds attached directly or indirectly through a linker arm thereto. Modifications to the nucleotides or to the oligo- or polynucleotides involve the pentosyl moieties, the abasic moieties (without a base) and the base moieties. Useful property changes are effected and can be measured or detected when such modified nucleic acids compositions have hybridized specifically to target nucleic acids.

Abstract: An apparatus for analyzing particles in urine comprising is disclosed that includes: a measurement specimen preparing section for preparing a measurement specimen by using a urine sample and a stain reagent; an optical detecting section comprising a light source for emitting a light to the prepared measurement specimen, a forward-scattered light receiving element for detecting forward-scattered light emitted from the specimen, a side-scattered light receiving element for detecting side-scattered light emitted from the specimen, and a fluorescence receiving element for detecting fluorescence emitted from the specimen; and a measurement section for measuring leukocytes in urine, based on the forward-scattered light, the side-scattered light and the fluorescence detected by the optical detecting section. A method for analyzing particles in urine is also disclosed.

Abstract: Disclosed is a microfluidic device including a microfluidic structure formed in a platform in which various examinations, such as an immune serum examination, can be automatically performed using the biomolecule microarray chip. The biomolecule microarray chip-type microfluidic device using a biomolecule microarray chip comprises: a platform which is rotatable; a microfluidic structure disposed in the platform, comprising: a plurality of chambers; a plurality of channels connecting the chambers each other; and a plurality of valves controlling flow of fluids through the channels, wherein the microfluidic structure controls flow of a fluid sample using rotation of the platform and the valves; and a biomolecule microarray chip mounted in the platform such that biomolecule capture probes bound to the biomolecule microarray chip contact the fluid sample in the microfluidic structure.

Abstract: An apparatus includes a system for guiding chemiluminescence and a system for preventing a variation in dark currents. The apparatus includes a first light shielding BOX having a sample container holder and a shutter unit therein, the shutter unit including a top plate which is partly formed by a movement of a plate member, and a second light shielding BOX having a photodetector therein. While a measurement is not implemented, the shutter unit is closed to block entrance of stray light to the photodetector, and while a measurement is implemented, the plate member is moved to open the shutter unit, and the tip of the photodetector is inserted into a through hole formed in the top plate, so that the distance between the bottom of the sample container and a sensitive area of the photodetector is reduced to several millimeters or less.

Abstract: A method for analysis of an object dyed with fluorescent coloring agents. Separately fluorescing visible molecules or nanoparticles are periodically formed in different object parts, the laser produces the oscillation thereof which is sufficient for recording the non-overlapping images of the molecules or nanoparticles and for decoloring already recorded fluorescent molecules, wherein tens of thousands of pictures of recorded individual molecule or nanoparticle images, in the form of stains having a diameter on the order of a fluorescent light wavelength multiplied by a microscope amplification, are processed by a computer for searching the coordinates of the stain centers and building the object image according to millions of calculated stain center co-ordinates corresponding to the co-ordinates of the individual fluorescent molecules or nanoparticles. Two-dimensional and three-dimensional images are provided for proteins, nucleic acids and lipids with different coloring agents.

Abstract: Methods and reagents are disclosed for pretreating a sample suspected of containing a hydrophobic drug for conducting an assay method for detecting the hydrophobic drug. A combination is provided in a medium that includes the sample, a releasing agent for releasing the hydrophobic drug and the metabolites from endogenous binding moieties, and a selective solubility agent that provides for substantially equal solubility of the hydrophobic drug and the metabolites in the medium. The selective solubility agent includes a water miscible, non-volatile organic solvent and is present in the medium in a concentration sufficient to provide for substantially equal solubility of the hydrophobic drug and the metabolites in the medium. The medium, which may further include a hemolytic agent, is incubated under conditions for releasing the hydrophobic drug and the metabolites from endogenous binding moieties. The pretreated sample may be subjected to an assay for determining the hydrophobic drug.

Abstract: The present invention relates to a apparatus for quantitative continuous real-time monitoring to monitor a continuous reaction of biochemical reagent and the reaction, such as DNA. More particularly, the present invention is directed to a miniaturized apparatus for real-time monitoring of biochemical reaction, which comprises capillary tubes (100) wherein biochemical reaction mixture flow; a thermal conduction block (120) which is coiled with capillary tube several rounds in order and composed of several blocks for temperature control of which temperatures are different from each other for heating or cooling the biochemical reaction mixture which flow in capillary tube, and a temperature controller which controls the temperature of above temperature control block; a radiation part (130) to radiate the reaction mixture flowing through the capillary tube and a light receiving section (140) which receives and measures the intensity of the fluorescence generated from the capillary tubes.

Abstract: The present invention provides microfabricated substrates and methods of conducting reactions within these substrates. The reactions occur in plugs transported in the flow of a carrier-fluid.

Abstract: Provided is a monoclonal antibody, or an antigen binding fragment thereof, which binds specifically to an epitope within the sequence KPGAKKDTKDSRPKL (Sequence ID No. 2) of AGR2. Such monoclonal antibodies are of prognostic and diagnostic utility in the investigation of cancer, particularly metastatic cancer. The antibodies described may also be used in prognosis or diagnosis of inflammatory diseases. Also provided are kits and solid supports comprising such antibodies, as well as the therapeutic use of antibodies of the invention.

Abstract: This invention relates to the detection and quantitation of target nucleic acids in a heterogeneous mixture in a Sample and the methods of use thereof. The detection system includes a chemiluminescent molecule, a chemiluminescent substrate, a dye that is light responsive when intercalated into nucleic acids and nucleic acids. This invention is useful in any application where detection of a specific nucleic acid sequence is desirable, or where the detection of enzymes that modify nucleic acids is desirable such as diagnostics, research uses and industrial applications.

Abstract: A sensor that generates an output signal in response to a stimulus, where the output signal is generated with a predetermined relationship to one or more properties of the stimulus such that the one or more properties of the stimulus can be determined as a function of the output signal. In one embodiment, the sensor includes a component, a sensor processor, and a transmitter. The component deteriorates, thereby causing predictable fluctuations in the predetermined relationship between the output signal and the one or more properties of the stimulus. The sensor processor provides information related to the deterioration of the component. The transmitter wirelessly transmits the information provided by the processor.

Abstract: A luminescence detecting apparatus and method for analyzing luminescent samples is disclosed. Luminescent samples are placed in a plurality of sample wells in a tray, and the tray is placed in a visible-light impervious chamber containing a charge coupled device camera. The samples may be injected in the wells, and the samples may be injected with buffers and reagents, by an injector. In the chamber, light from the luminescent samples pass through a collimator, a Fresnel field lens, a filter, and a camera lens, whereupon a focused image is created by the optics on the charge-coupled device (CCD) camera. The use of a Fresnel field lens, in combination with a collimator and filter, reduces crosstalk between samples below the level attainable by the prior art. Preferred embodiments of the luminescence detecting apparatus and method disclosed include central processing control of all operations, multiple wavelength filter wheel, and robot handling of samples and reagents.

Abstract: Fluid analyte sensors include a photoelectrocatalytic element that is configured to be exposed to the fluid, if present, and to respond to photoelectrocatalysis of at least one analyte in the fluid that occurs in response to impingement of optical radiation upon the photoelectrocatalytic element. A semiconductor light emitting source is also provided that is configured to impinge the optical radiation upon the photoelectrocatalytic element. Related solid state devices and sensing methods are also described.

Abstract: A method for identifying the redox activity of a subject compound is disclosed. The method can be performed aerobically and can include forming a mixture comprising a free-radical precursor and a compound to be tested, and converting the free-radical precursor into a free-radical anion and a free-radical cation. After the free radical cation and the free radical anion have been formed, the relative redox activity of the subject compound may cause a difference in the rate of photo-bleaching of the mixture and/or the rate of superoxide generation. These differences can be quantified and used to identify the redox activity of the subject compound. This sensitive technique for measuring redox activity can be used to screen compounds for various biological applications. Drugs also can be developed based on the relationship between redox activity and biological activity for particular biological applications.