Abstract: Electrokinetic devices having a computer for correcting for electrokinetic effects are provided. Methods of correcting for electrokinetic effects by establishing the velocity of reactants and products in a reaction in electrokinetic microfluidic devices are also provided. These microfluidic devices can have substrates with channels, depressions, and/or wells for moving, mixing and monitoring precise amounts of analyte fluids.

Abstract: A field test kit for gunshot residue comprises a container having at least compartments separated by a barrier. A surface is tested by wiping it with a swab and placing the swab in a first compartment. The barrier is then breached, permitting reagent in the second compartment to flow onto the swab. The first compartment is transparent, and a color change will be observed if the reagent reacts with gunshot residue.

Abstract: A chromatography immunoassay device is described which can be used more easily, is protected from moisture and/or oxygen more effectively and can be produced at a lower cost than known chromatography immunoassay devices. The chromatography immunoassay device of the present invention is one in which one or more chromatography strips are stuck on a substrate made of a plate, each of the chromatography strips is sealed by closely adhering a substrate portion surrounding each chromatography strip to a seal film located on the chromatography strip, and the seal film and/or substrate possesses a film containing a dehumidifying agent and/or a film containing an oxygen absorbing agent.

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 provides novel microfluidic devices and methods that are useful for performing high-throughput screening assays. In particular, the devices and methods of the invention are useful in screening large numbers of different compounds for their effects on a variety of chemical, and preferably, biochemical systems.

Abstract: Disclosed are devices for detecting the presence of a preselected analyte in a fluid sample. The devices comprise a substrate microfabricated to define a sample inlet port, and a mesoscale flow system that includes a sample flow channel extending from the inlet port. The mesoscale flow system further includes an analyte detection region in fluid communication with the flow channel comprised of a binding moiety for specifically binding the analyte. The detection region is constructed with a mesoscale dimension sufficiently small to enhance binding of the binding moiety and the analyte. The binding moiety may be immobilized in the detection region. The mesoscale detection systems of the invention may be used in a wide range of applications, including the detection of cells or macromolecules, or for monitoring reactions or cell culture growth.

Abstract: The present invention describes novel methods for making a substrate for selective cell patterning, and the substrates themselves, wherein the method comprises contacting reactive hydroxyl groups on the surface of a substrate with a hydroxyl-reactive bifunctional molecule to form a monolayer, and using stencils to deposit cell repulsive or cell adhesive moieties in controlled locations on the cell culture substrate. Methods comprising selective differentiation of stem cells to create tissue specific and organ-specific cell substrates, as well as the cell substrates themselves are also provided.

Abstract: Disclosed are biochips having a high detecting sensitivity with readiness in fabrication of microarray, and a method for fabricating the same, in which a solid support wound with fibers is immersed in a solution containing biomolecules to immobilize the biomolecules onto the fiber, and the individual fibers with the biomolecules immobilized thereon are straightened and arranged. The arranged fibers are embedded with a defined material and cut in a direction perpendicular to the lengthwise arrangement direction of the fibers to obtain thin chips. The chips are placed on a substrate to remove the material used for embedding and thereby remain fibers with the immobilized biomolecules on the substrate. This biochip fabrication method immobilizes a great number of biomolecules onto the fibers having a large surface area to enhance the detection sensitivity and allows production of a great number of substrates with an array of biomolecules immobilized simultaneously.

Abstract: An immunoassay for selectively measuring human C-peptide as well as a kit therefor is disclosed. In the method, human C-peptide contained in a sample, a first anti-human C-peptide antibody, and a second anti-human C-peptide antibody which is immobilized on a solid support are reacted to form an immune complex among these three components. The formed immune complex is separated from the non-reacted antibodies and sample; and then the separated immune complex is quantified. The first antibody recognizes an epitope existing in the region from 1st to 16th amino acid residue from the N-terminal of the human C-peptide, and the second antibody recognizes an epitope existing in the region from 1st to 16th amino acid residue from the N-terminal of human C-peptide; with the proviso that the first and second antibodies do not recognize the same epitope so that they can simultaneously bind to said human C-peptide.

Abstract: Devices and methods for conducting binding reactions are described. The devices comprise first and second surfaces with channels extending between them. Specific binding reagents are immobilized in discrete groups of the channels. Sample passing through the channels reacts with the binding reagents. Binding of the sample component to the binding reagent in different groups of channels is detected providing information about sample composition. The devices provide increased surface area and accelerated reactions kinetics compared with flat surfaces.

Abstract: Electrokinetic devices having a computer for correcting for electrokinetic effects are provided. Methods of correcting for electrokinetic effects by establishing the velocity of reactants and products in a reaction in electrokinetic microfluidic devices are also provided. These microfluidic devices can have substrates with channels, depressions, and/or wells for moving, mixing and monitoring precise amounts of analyte fluids.

Abstract: An array bundle is provided for creating multiple arrays for testing. The array bundle is adapted to be cut transversely to form a series of identical arrays of cells. In one embodiment, the array bundle is used in detecting predetermined components from sample mixtures.

Abstract: A method and apparatus for magnetic separation of particles within a container. In one embodiment, a container contains a number of particles and a number of magnetically susceptible particles. A number of magnets are arranged in a plane and is placed close to the container. The magnetic poles of the magnets are arranged in a pattern to apply magnetic fields oriented perpendicular to the plane on the container. The pole pattern provides in consistent separation across the container of the number of magnetically susceptible particles from the rest of the particles.

Abstract: Subject matter of the invention is a method for detecting surface contamination by an analyte by wiping the analyte off the surface with the aid of a wiping surface, eluting the analyte from the wiping surface with an eluant, and detecting the analyte in the eluate in an immunological detection reaction, characterized in that: a) the surface to be tested for the analyte is wiped with a wiping surface, b) the wiping surface is brought into contact with the planar surface of a capillary active, chromatographic test strip which has an eluant application zone at its one end and a target zone at its other end whereby contact is made in an area between these two zones, c) eluting liquid is applied onto the zone provided for this purpose, said liquid moving toward the target zone passes the contact site with the wiping surface as a consequence of capillary forces, whereby analyte is taken up by the eluant, and d) in the target zone, the analyte is measured in an immunological binding reaction.

Abstract: A system for producing substantially identical specific binding ligand (e.g., nucleic acid) probe arrays, for instance, by preparing and replicating an original master array and/or by providing a reusable assay array that is capable of being regenerated. In one embodiment the system includes the preparation and use of a) a master array surface having address sequences immobilized in the form of a patterned, and optionally random, array, b) a multi-ligand conjugate having a binding domain complementary to an address sequence, a binding domain complementary to a target sequence, and a third ligand for use in forming (e.g., by binding or polymerization) the conjugates into or onto the surface of assay array, which can be used with or upon disassociation of the address and its complementary sequences.

Abstract: A method for quantitatively and/or qualitatively assaying an analyte in a sample, wherein the analyte is a receptor binding compound, has low detection limits equivalent to those of radioreceptor assays. The method comprises the steps of a) contacting the sample with material comprising a receptor for the analyte in order for receptor-analyte binding to occur and b) further contacting the sample with a detectable ligand for the receptor in order for receptor-ligand binding to occur, followed by c) separating the resulting receptor bound and free fractions, d) subjecting the receptor bound fraction to dissociating conditions releasing the ligand from the receptor and e) assaying for the dissociated ligand in a manner known per se for the detection of the detectable ligand.

Abstract: The invention relates to an apparatus for inhibiting bubble formation during a chemical reaction. The apparatus comprises a base having a substantially planar surface with at least a portion of the surface representing a fluid contact area and a fluid comprising a liquid component in contact therewith. A cover and the base form an enclosure containing the fluid and a gas. A non-free-floating fluid-distribution member is provided that has a substantially flat surface in contact with the fluid. The member surface is disposed in an opposing and substantially parallel manner at a specified distance from fluid contact area. A gas-fluid interface having an interface radius is formed between the fluid and the gas. The apparatus also comprises means for maintaining a desired vapor pressure of the liquid component in the gas and means for immobilizing the cover with respect to the base. The interface radius is selected to result in a predetermined critical radius below which a bubble will shrink.

Abstract: The invention provides a method for measuring the amount of analyte in a sample of biological fluid using a simple low sample volume reagent test strip with a built in metering system. The test strip may comprise a microtitration zone to prevent oversampling and an integrated capillary to prevent problems associated with short sampling and act as means of absorbing the fluid sample. The test strip comprises a wicking layer and a reaction matrix embossed layer in the form of a pillow assembled into a microtitration pocket formed in the strip. The test strip is used in single use applications such as the determination of the concentration of glucose in blood.

Abstract: The invention relates to a novel competitive or non-competitive immunoassay comprising the steps of immobilizing an assay specific component on a solid phase in a reaction well, adding a labelled assay specific component, drying said components, adding the sample containing the marker to be analyzed, allowing the marker to react with the assay specific components, and detecting the signal from the label. Furthermore, the invention relates to a device useful in carrying out the novel assay.

Abstract: The present invention provides systems, methods, screens, reagents and kits for optical system analysis of cells to rapidly determine the distribution, environment, or activity of fluorescently labeled reporter molecules in cells for the purpose of screening large numbers of compounds for those that specifically affect particular biological functions.

Abstract: The present invention provides novel microfluidic devices and methods that are useful for performing high-throughput screening assays. In particular, the devices and methods of the invention are useful in screening large numbers of different compounds for their effects on a variety of chemical, and preferably, biochemical systems.

Abstract: A device and method for separating a fluid component from a non-fluid component of a sample comprises a plurality of microspheres disposed in abutting relation and forming therebetween a plurality of capillary channels, whereby when the microspheres are disposed in fluid communication with a sample the fluid component is separated from the non-fluid component by capillary flow of the fluid component through the capillary channels formed by the interstitial spacing between abutting microspheres.

Abstract: A compact assay system having a solid support has at least one capture binding agent on the support surface. By applying a combination of different binding agents on the support surface, the present invention can conduct multiple chemical reactions on the support solid support to detect analytes of interest. The specific reagents, or capture binding agents, are preferably immobilized on the solid support by means of a computer controlled, miniaturized printing system. Specifically, the reagents can be applied onto the solid support using a commercial available printhead of an ink-jet printer. In addition, the support surface also includes areas adapted to be digitally readable by laser to store information concerning binding between capture agents and analytes. The assay system is useful as a sample array holder for performing a variety of chemical analyses, such as matrix assisted laser desorption ionization mass spectrometry analyses.

Abstract: Methods of detecting and quantifying genomic nucliec acid molecule sequences are provided using the simultaneous amplification of a plurality of discrete nanoliter-sized samples. A miniaturized closed assembly is also provided for carrying out amplification of a nucleic acid molecule by polymerase chain reaction in multiple nanoliter-sized samples. Methods of filling miniaturized sample chambers are also provided as are methods for determining the number of template molecules in a sample by conducting replicate nucleic acid sequence amplification reactions on a set of terminally diluted samples and counting the number of positive amplification reactions. The methods can be used to detect a single starting nucleic acid target molecule.

Abstract: A cartridge for separating a desired analyte from a fluid sample has a sample flow path and a lysing chamber in the sample flow path. The lysing chamber contains at least one filter for capturing cells or viruses from the sample as the sample flows through the lysing chamber. Beads are also disposed in the lysing chamber for rupturing the cells or viruses to release the analyte therefrom. An analyte flow path extends from the lysing chamber and diverges from the sample flow path. The analyte flow path preferably leads to a reaction chamber for chemically reacting and optically detecting the analyte. The cartridge also includes at least one flow controller (e.g., valves) for directing the sample into the waste chamber after the sample flows through the lysing chamber and for directing the analyte separated from the sample into the analyte flow path.

Abstract: A multi-slide assembly includes various components that alone or in combination facilitate testing of test samples with minimal manipulation of assay components. Moreover, the various device components permit centrifugation, culturing and analysis of each test sample to be performed in the same assembly. A frame retains a plurality of reaction vessel assemblies between a pair of opposing channels that are configured to slidably receive the opposing ends of each reaction vessel assembly. A strip cap seals the openings in each reaction vessel using cap members having sealing rings circumscribing the external walls thereof to form compression seals with internal walls of the reaction vessels. Furthermore, in a method of making a multi-well slide assembly, an ultrasonic welding process removably bonds a plurality of wells to a slide plate to provide an adequate seal therebetween during centrifugation, yet still enable separation thereof by an operator.

Abstract: Compositions and methods for the detection of adult Taenia solium and the diagnosis and treatment of T. solium infection are described. The compositions contain one or more adult T. solium polypeptides. The polypeptides are useful as diagnostic agents for the detection of adult tapeworm infection. More preferably, the polypeptides are T. solium glycoprotein antigens referred to herein as T. solium excretory/secretory (TS/ES) polypeptides. The most preferred TS/ES polypeptide has a molecular weight of approximately 33 kDa, 38 kDa, or 42 kDa as determined by SDS-PAGE analysis.

Abstract: The present invention concerns methods of testing water for microbe contamination. The methods of the invention comprise supplementing existing methods with assays using specific reagents such as monoclonal antibodies. The invention also concerns a device for use in the methods of the invention.

Abstract: A compact assay system having a solid support has at least one capture binding agent on the support surface. By applying a combination of different binding agents on the support surface, the present invention can conduct multiple chemical reactions on the support solid support to detect analytes of interest. The specific reagents, or capture binding agents, are preferably immobilized on the solid support by means of a computer controlled, miniaturized printing system. Specifically, the reagents can be applied onto the solid support using a commercial available printhead of an ink-jet printer. In addition, the support surface also includes areas adapted to be digitally readable by laser to store information concerning binding between capture agents and analytes.

Abstract: A method and apparatus for analyzing molecular structures within a sample substance using an array having a plurality of test sites upon which the sample substance is applied. The invention is also directed to a method and apparatus for constructing molecular arrays having a plurality of test sites. The invention allows for definitive high throughput analysis of multiple analytes in complex mixtures of sample substances. A combinatorial analysis process is described that results in the creation of an array of integrated chemical devices. These devices operate in parallel, each unit providing specific sets of data that, when taken as a whole, give a complete answer for a defined experiment. This approach is uniquely capable of rapidly providing a high density of information from limited amounts of sample in a cost-effective manner.

Abstract: A microchip device for electrophoresis includes not only a microchip having a separation flow route for separating a sample electrophoretically and an electrical power source for applying a migration potential difference along the separation flow route but also a grating for dispersing light received from each position within a specified range along the separation flow route in a direction perpendicular to the separation flow route, a two-dimensional light-receiving device such as charge-coupled devices for receiving dispersed light from the grating at light-receiving positions which are two-dimensionally distributed parallel to and and perpendicular to the separation flow route, and a data processor for receiving measured values obtained repeatedly by said two-dimensional light-receiving means and carrying out multi-point averaging on the measured values for each of the light-receiving positions.

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: A method to produce arrays of compounds for concurrent testing is described. Two formats are described using porous rods or porous sheet materials. In one format, the compounds of the array are immobilized onto porous rod elements. In the second format, the compounds are immobilized as lines on a sheet of porous material. In both cases, a bundle is formed by radial compression of the rods or spiral wrapping of the sheet. A sheath is applied to the bundle, and arrays are cut as slabs. Each synthesis or application step to create an array element is used to fabricate multiple arrays. Relatively high-density arrays can be produced with current printing technologies. The method is particularly suited to mass production of arrays.

Abstract: Method and test kit for assaying in a sample an analyte which is a bloodgroup antigen present on erythrocytes or an antibody binding to such a bloodgroup antigen. To that end, the sample is treated with a reagent containing a binding partner for the analyte, so that a complex of bloodgroup antigen present on erythrocytes and antibody bound thereto is formed if the sample contains analyte. The analyte is a bloodgroup antigen present on erythrocytes, the analyte binding partner is an antibody capable of binding to the bloodgroup antigen and if the analyte is an antibody binding to a bloodgroup antigen, the analyte binding partner is the bloodgroup antigen present on erythrocytes. Erythrocytes, complex or non-complexed, are then separated from non-bound antibodies using a separation medium with a density higher than that of the liquid containing the antibodies but lower than the density of crythrocytes.

Abstract: The invention includes assay cassettes that can be employed during rapid flow-through binding assays. The assay cassettes can be disposable units suitable for one-time use and readily assembled to include a filter membrane carried between an upper plate and a lower plate. A pattern of channels can extend through the top plate to allow a fluid sample to be applied through the top plate and onto the filter. The bottom plate can include a plurality of channels that are aligned with the channel of the top plate and which will allow a negative pressure to be applied to the underside of the filter membrane to draw the sample through the filter. In one embodiment, the cassette includes a frangible section that allows the cassette to be divided into a first and second component.

Abstract: A slide having a portion thereof provided with transparent adhesive which adheres to a test sample. The slide and adhesive may be transparent. Specific types of infection and particularly fungal infections can be detected in the test sample using immunotest-methods. In a special embodiment the adhesive slide is fashioned with a peripheral lip or well to contain a test sample and a reagent.

Abstract: A apparatus for assaying glycated proteins and other analytes in biological samples such as blood, in which a sample is presented to the apparatus, includes an inlet port between moveable between first and second inlets, such that the inlet can be brought into liquid communication with each inlet in turn. The inlet port accommodates a filter or binder. The apparatus also includes a microprocessor operable via a key pad, at least one light emitter and at least one light detector, a display and driver, and an A to D converter, and is operatively connected to a power source.

Abstract: An analytical system comprises a frame and movable carriage. An analytical rotor is mounted on the carriage and can be translated among a sample dispensing station, a fluid dispensing station, and a label detection zone. In order to perform assays, the analyzer system requires only the introduction of the analytical rotor, sample, and a volume of diluent solution. Sample within the analyzer is contained at all times within either a sample receptacle or the rotor. The method allows for the sequential addition of sample and diluent in order to perform multiple assay steps and is particularly suitable for performing heterogeneous immunoassays. The use of fluorescent label in the system allows multiple analyte detection reactions to be performed from a single sample applied to a single rotor.

Abstract: The present invention concerns a method for separating at least one species of biological entities from a sample solution, by contacting the sample with a matrix of magnetic particles formed on a substrate such as a sheet a gel, etc. The particles in the matrix are coupled to entities capable of specifically binding to the species of biological entities to be separated. The separation is carried out either for detection purposes for obtaining separately each species of biological entities or for synthesis purposes. The invention further concerns matrices of magnetic particles formed on various substrates and kits for use in the method.

Abstract: There is used at least one probe array obtained by arraying particles having various probes, respectively, fixed thereon (probe particles) in a definite order in a holder. A plurality of capillaries or grooves packed with various kinds, respectively, of probe particles are arrayed in parallel, and one of particles contained in each capillary or groove is injected into another capillary or groove to produce a probe array in which the various kinds of probe particles are arrayed in a constant and definite order. Various fluorophore-labeled DNA's are measured at the same time by attaching various probes to particles, respectively, of different sizes. A probe array composed of various fixed DNA probes can easily be produced, and there can be provided a probe array for detecting various DNA's which is composed of various fixed arbitrary DNA probes.

Abstract: The invention describes quality control devices for assays that measure analytes in cells and tissue samples, and methods of use thereof. In particular, the quality control device comprises a matrix affixed with synthetic controls in different concentrations, or different synthetic controls. The quality control device can be adhered to a microscope slide and processed simultaneously with a tissue sample.

Abstract: Analytical test kits and assay procedure employs test cards or strips of an inert plastic carrier having a flat, non-absorbent surface, containing thereon spots of insolubilized reagent for the determination of an analyte, such as an antigen or an antibody, in a liquid medium such as serum or other body fluids in a solid phase enzyme immunoassay of the sandwich type. Different binding partners can be placed as separate spots on the same card for the assay of a group of related or unrelated analytes in the same test sample. An insoluble colored product on a spot, qualitatively and quantitatively, is indicative of a positive result.

Abstract: The invention relates to a method and apparatus for detecting specific target cells in a simple and time-saving way, using paramagnetic particles, antibodies recognizing the Fc portions of target-cell associating antibodies and target-cell associating antibodies directed to specific antigen determinants in the target-cell membranes. Incubation of the cell suspension with detergent and/or second antibodies or antibody fragments, prelabeled or not with fluorescent agents, metallocolloids, radioisotopes, biotin complexes or certain enzymes allowing visualization, dramatically increase the specificity of the method. The method and apparatus described provides a solid support and permanent record which is easily viewed by microscopy, permits viewing and quantification of the whole specimen rather than small fractions thereof and allows the use of large specimen volumes to be analysed, the device may also be scanned automatically by conventional densitometric technology.

Abstract: A method and apparatus for preparation of a substrate containing a plurality of sequences. Photoremovable groups are attached to a surface of a substrate. Selected regions of the substrate are exposed to light so as to activate the selected areas. A monomer, also containing a photoremovable group, is provided to the substrate to bind at the selected areas. The process is repeated using a variety of monomers such as amino acids until sequences of a desired length are obtained. Detection methods and apparatus are also disclosed.

Abstract: The invention provides an ex-vivo test kit for testing the effectiveness of reversers of multidrug resistance in the blood, serum or plasma of a patient containing the reversers, the kit comprising, a plurality of cell membranes from highly drug-resistant cells, the cell membranes containing proteins which pump drugs and the membranes being respectively attached to a plurality of support surfaces, and a dye which provides a light signal, which dye is pumped by the proteins contained in the membranes.

Abstract: An assay plate for detecting the presence of a mobile reactant that binds to a immobilized reactant and the methods of making and using the same. An assay plate according to the present invention includes a substrate and at least one dried aliquot of the immobilized reactant, the immobilized reactant being bound to the surface of the substrate. The immobilized reactant binds the mobile reactant when a solution containing the mobile reactant is brought into contact with the immobilized reactant. The mobile and immobilized reactants may be any pair of biological compounds that have a specific affinity for one another For example the reactants may be nucleic acids or antibody-antigen pairs.

Abstract: An apparatus and method of use for assaying cellular motility in response to a concentration gradient of a chemotactic agent. Generally, the apparatus includes a chamber having a region for receiving a biological sample containing cells of interest and, spaced apart from such region, another region for receiving a chemotactic agent. Between these regions, a concentration gradient of chemotactic agent is established. The apparatus further includes an optical system for detecting and mapping the positions of individual cells responsive to such concentration gradient. Means for processing and analyzing the collected data are also provided. Motility determinations may be made on purified or unpurified samples. Single-site assay devices and multi-site, high-throughput assay devices are disclosed.

Abstract: Formed constituents of a quiescent anticoagulated whole blood sample are optically or visually analyzed in a sample chamber which has a varying through plane thickness due to convergent opposing sample chamber walls. At least one of the convergent walls of the chamber is transparent so that the blood sample constituents can be observed. The chamber's varying thickness produces a first lesser thickness region in the chamber wherein a quiescent monolayer of red blood cells in the sample will reside after the sample is introduced into and fills the chamber. Larger formed constituents such as white blood cells in the sample are unable to enter the aforesaid lesser thickness region of the chamber. The red cells which reside in the greater thickness regions will agglomerate to form rouleaux and lacunea. The exact thickness of the chamber at any particular location in the chamber can be predetermined, or can be determined in situ as the sample is being analyzed.

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 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 further provides a method of determining bound and free analyte in a sample using at least one photon reducing agent. The present invention also provides a method of screening test chemicals in fluorescent assays using photon reducing agents.