189 results about "Fluorescence assay" patented technology

A method and device for fluorimetric determination of a biological, chemical or physical parameter of a sample utilize at least two different luminescent materials, the first of which is sensitive to the parameter, at least with respect to luminescence intensity, and the second of which is insensitive to the parameter, at least with respect to luminescence intensity and decay time. The luminescent materials have different decay times. The time- or phase behaviour of the resulting luminescence response is used to form a reference value for determination of a parameter.

Disclosed is a microassay testing system, including a microfluidic cartridge and a compact microprocessor-controlled instrument for fluorometric assays in liquid samples, the cartridge having integrated process controls and positive and negative assay controls. The instrument has a scanning detector head incorporating multiple optical channels. In a preferred configuration, the assay is validated using dual channel optics for monitoring a first fluorophore associated with a target analyte and a second fluorophore associated with a process control. Integrated positive and negative assay controls provide enhanced assay validation capabilities and facilitate analysis of test results. Applications include molecular biological assays based on PCR amplification of target nucleic acids and fluorometric assays in general.

An instrument for fluorometric assays in liquid samples is disclosed. The instrument may include multiple optical channels for monitoring a first fluorophore associated with a target analyte and a second fluorophore associated with a control. The disclosed instrument finds utility in any number of applications, including microfluidic molecular biological assays based on PCR amplification of target nucleic acids and fluorometric assays in general.

A fluorometry device and method adapted to determine concentration of spectrally distinguishable species in a biological sample with a plurality of movable optical devices.

In response to the need for highly-sensitive antibiotic susceptibility assays and identification assays that do not require extensive incubation times, the present invention provides automated assay methods and systems that permit the determination of antibiotic susceptibilities and/or microorganism identification in a timeframe that is substantially shorter than has previously been attainable using a hybrid system that combines turbimetric and fluorescence determinations using a single, clear-plastic assay platform. Related devices, kits, and components thereof are also disclosed.

The invention relates to a method for determining the amount of nucleic acid present in a sample, wherein:—a fluorophore is added to the sample,—fluorescence intensities emitted by the fluorophore at least two emission wavelengths in response to light stimulations at least two excitation wavelengths respectively are measured, and—the amount of nucleic acid present in the sample is deduced from the measured fluorescence intensities.

This invention provides a method of detecting pathogens comprising the steps of: (a) contacting a sufficient amount of biofunctional magnetic nanoparticles with an appropriate sample for an appropriate period of time to permit the formation of complexes between the pathogens in the sample and the nanoparticles; (b) using a magnetic field to aggregate said complexes; and (c) detecting said complexes. The method may further comprise the additional step of removing said complexes. The biofunctional magnetic nanoparticles are preferably a conjugate of vancomycin and FePt. The pathogens may be bacteria or viruses, and the sample may be a solid, liquid, or gas. Detection may involve conventional fluorescence assay, enzyme-linked immunosorbent assay (ELISA), optical microscope, electron microscope, or a combination thereof. The sensitivity of detection for the method is at least as low as 10 colony forming units (cfu) of the pathogens in one milliliter of solution within one hour.

An instrument is disclosed for fluorescence assays which is capable of reading many independent samples at the same time. This instrument provides enhanced throughput relative to single-sample instruments, and is well-suited to use in general fluorescence, time-resolved fluorescence, multi-band fluorescence, fluorescence resonance energy transfer (FRET), and fluorescence polarization. This invention is beneficial in applications such as high-throughput drug screening, and automated clinical testing. Also disclosed are means and methods for a fluorescence polarization measurement which is highly sensitive, inherently self-calibrated, and unaffected by lamp flicker or photobleaching. This fluorescence polarization invention can be practiced on a variety of fluorescence instruments, including prior-art equipment such as microscopes and multi-well plate readers.

A functional lanthanide fluorescence nanoparticle (LFNP) is prepared from the strong-fluorescent RE matches as luminous center through chemically wrapping by silica gel. Its advantages are long fluorescence lift, big stoke shift, narrow emitting peak and strong specific signal. It can be used as the fluorescent marker for biological detection.

A method for preparing flow cytometer -micro carrier clinical diagnosis chip includes fixing different biological molecules on micro carrier then labeling them with fluorescence in different intensity to form a fluorescent gradient, using micro carrier-biological molecule to culture with sample and combining it with ligand, confirming micro carrier with different size and obtaining micro carrier in different diameter region when flow cytometer is on gravest, selecting micro carrier in different size and using its own fluorescence to compare with detection fluorescence for determining ligand to be tested, providing said chip for clinically diagnose infectivity disease, taraxy disease, autoimmune disease, etc..

The invention discloses a method for determining the CMC (critical micelle concentration) of surfactant. The new method for determining the CMC of surfactant is designed by using an aggregation-induced emission organic substance having a structure shown in Formula (I) as a fluorescent probe according to the characteristics of the organic substance. The method is to determine the CMC through the highest fluorescence intensity mutation point of the probe, while the CMC fluorescent determination method reported by others is to determine the CMC through the lowest fluorescence intensity mutation point of the probe. Therefore, the CMC fluorescent determination method disclosed by the invention has higher sensitivity in comparison with the reported CMC fluorescent determination method. According to the CMC fluorescent determination method disclosed by the invention, when surfactant detection solutions of different concentrations are prepared, the concentration of the fluorescent probe does not need to be maintained at the same level, thus greatly simplifying the operation steps and eliminating the error caused by measuring the fluorescent probe repeatedly. The Formula (I) is shown in the specification.

The present invention relates to new europium complex fluorescent probe for the imaging determination of singlet oxygen in live cell and its application. The fluorescent probe is complex formed with trivalent europium ion Eu3+ and organic ligand [4'-(10-methyl-9-anthryl)-2, 2':6'2''-tripyridyl-6, 6''-dimethyl amino] tetracetic acid as shown. The complex can enter to live cell simply in the presence of photosensitizer and capture singlet oxygen in cell specifically, leading to obviously enhanced fluorescence strength of the complex for the fluorescent determination of singlet oxygen in live cell.

This invention relates to a kind of beta- diketone-triatomic europium complex nanometer fluorescent probe and its preparation and application. Its steps are the following: the monomer which can copolymarized with silicate ester takes conjugated bonding reaction with beta- diketone-triatomic europium complex in organic solvent and then takes copolymerization with silicate ester to form functional nanometer rare earth fluorescence particles. The said triatomic europium ion, beta - diketone organic complex and the monomer and silicate ester take the mol proportion as 1 : 2-3 : 10-100 : 350-450. The particles is of higher fluorescence and stability and has in its surface with active function group directly used for biological marking and is free of interference of scattered light and short light when used for detecting time-resolution fluorescent. This invention is of high value in fields of time-resolution fluorescent immune detecting, cell chemistry, microscope forming, DNA crossing detecting and biological chip detecting.

A method of assaying compounds for their ability to effect enzymes including enhancing or inhibiting the effect of those enzymes on double stranded DNA sequences is disclosed. The method comprises providing a modified nucleotide sequence comprised of a base analogue which analogue is characterized by increased fluorescence when moved out of its normal helical position, the sequence having a complimentary sequence hybridized thereto to provide a double stranded sequence. The modified sequence containing the base analogue is brought into contact with the enzyme which enzyme is characterized by effecting the 3-dimensional position of the analogue within the sequence. The enzyme is brought into contact with the sequences in the presence of a compound being assayed. By knowing the amount of increased fluorescence the enzyme would normally have on the sequence is possible to determine the inhibitory or enhancing effect of the compound on the enzyme.

The invention discloses an OH free radical measurement calibration system by adopting fluorescence assay by gas expansion. The OH free radical measurement calibration system comprises a wideband light source, a water vapor generation part, an OH free radical generation part and a signal collection part, wherein the OH free radical generation part comprises an aluminum cavity, a U-shaped air inlet pipe, a multiple-reflection cell, a quartz sleeve and a high power ultraviolet lamp. The OH free radical calibration system disclosed by the invention can integrate generation and measurement of OH free radicals, and the concentration of the generated OH free radicals is measured by adopting a differential optical absorption spectroscopy (DOAS), so that the accuracy of the measured concentration of the OH free radicals is improved; the concentration of the OH free radicals is measured by adopting an optical method, the collection system is simple, and convenient and easy to operate; the wideband light source is adopted by the OH free radical calibration system disclosed by the invention, and visible light in the light source is used as an indication and adjustment light source of 308nm to solve the problem that the optical distance of the multiple-reflection cell is hard to measure due to the invisibility of 308nm.

The invention provides a 1-(7-ethoxycoumarin)-4-(2-methyl-8-methoxyquinoline)-1, 2, 3-triazole ratiometric fluorescence or ratiometric ultraviolet absorption probe agent and preparation and application thereof, and belongs to the technical fields of organic synthesis and analytic chemistry. The preparation method is characterized in that an intermediate, namely, 2-methyl-8-(propyn-2-yl alkoxy) quinoline, reacts with 7-(2-azidoethoxy)-coumarin to obtain a compound a of which triazolyl is connected with two fluorophores, namely, coumarin and quinoline, wherein the compound is 1-(7-ethoxycoumarin)-4-(2-methyl-8-methoxyquinoline)-1, 2, 3-triazole. The preparation method has the advantages that the reaction raw materials are easy to obtain, the synthesis method is simple, and the compound can be obtained by three-step reaction; the compound a generates ratiometric fluorescence at 480nm and 390nm in alcohol/aqueous solution, and trace Al<3+> can be measured accordingly; ratiometric ultraviolet absorption is produced at 253nm and 243nm, and trace Al<3+> can be measured accordingly. The probe agent is the probe agent being high in sensitivity, high in accuracy and high in selectivity and used for detecting Al<3+> ions through ratiometric fluorescence and ratiometric ultraviolet absorption. The structure formula of the compound a is as shown in the specification.

The present invention provides a sensor and methods for determining kinase activity.

The present invention provides for a polypeptide aggregation screening assay for the purpose of detecting modulators of polypeptide aggregation, which can provide for new therapies in pathologic states associated with polypeptide aggregation, especially considered is Alzheimer's Disease.

A fluorometric apparatus capable of configuring to have a small size and operability requiring a simple and easy operation of centrifuging a specimen in a container a rotation center of which is detachably supported by a rotation axis (not shown), exciting the specimen by means of an N₂ laser apparatus and an excitation light irradiator for guiding the laser light emitted from the N₂ laser apparatus, and receiving fluorescence having two types of wavelengths emitted from antibodies labeled with fluorescent dyes in the specimen in a region separate from the region in which the excitation light is radiated by a predetermined angle by using a photomultiplier tube, obtaining a ratio of light intensity for each wavelength, comparing the obtained ratio with a standard value, and estimating a target protein concentration.

The invention discloses preparation of a three-dimensional metal-enhanced fluorescent/colorimetric dual-mode paper chip and a method for measuring ATP by using a fluorescent/colorimetric dual-mode sensor. A hydrophobic area, a hydrophilic area and a hollow channel are prepared on the paper chip by using a wax printing technology, and the hollow channel is cut through a laser cutting machine. Gold and silver nanostars are grown in a working area 1, then a fluorescent signal material is fixed, and later a fluorescent quenching agent is dropwise added, so that ATP highly-sensitive fluorescent measurement is realized through the fluorescent signal 'off-on'. The prepared paper chip can be folded, and hydrogen peroxide is dropwise added in the reaction area, so as to realize ATP visual colorimetric measurement.