1860results about "Luminescent dosimeters" patented technology

The Laser Induced Fluorescence Attenuation Spectroscopy (LIFAS) method and apparatus preferably include a source adapted to emit radiation that is directed at a sample volume in a sample to produce return light from the sample, such return light including modulated return light resulting from modulation by the sample, a first sensor, displaced by a first distance from the sample volume for monitoring the return light and generating a first signal indicative of the intensity of return light, a second sensor, displaced by a second distance from the sample volume, for monitoring the return light and generating a second signal indicative of the intensity of return light, and a processor associated with the first sensor and the second sensor and adapted to process the first and second signals so as to determine the modulation of the sample. The methods and devices of the inventions are particularly well-suited for determining the wavelength-dependent attenuation of a sample and using the attenuation to restore the intrinsic laser induced fluorescence of the sample. In turn, the attenuation and intrinsic laser induced fluorescence can be used to determined a characteristic of interest, such as the ischemic or hypoxic condition of biological tissue.

An optical detection and orientation device is provided comprising housing having an excitation light source, an optical element for reflecting the excitation light to an aspherical lens and transmitting light emitted by a fluorophore excited by said excitation light, a focussing lens for focusing the emitted light onto the entry of an optical fiber, which serves as a confocal aperture, and means for accurately moving said housing over a small area in relation to a channel in a microfluidic device. The optical detection and orientation device finds use in identifying the center of the channel and detecting fluorophores in the channel during operations involving fluorescent signals.

The invention provides imaging apparatus and methods useful for obtaining a high resolution image of a sample at rapid scan rates. A rectangular detector array having a horizontal dimension that is longer than the vertical dimension can be used along with imaging optics positioned to direct a rectangular image of a portion of a sample to the rectangular detector array. A scanning device can be configured to scan the sample in a scan-axis dimension, wherein the vertical dimension for the rectangular detector array and the shorter of the two rectangular dimensions for the image are in the scan-axis dimension, and wherein the vertical dimension for the rectangular detector array is short enough to achieve confocality in a single axis.

Methods and systems for real-time monitoring of optical signals from arrays of signal sources, and particularly optical signal sources that have spectrally different signal components. Systems include signal source arrays in optical communication with optical trains that direct excitation radiation to and emitted signals from such arrays and image the signals onto detector arrays, from which such signals may be subjected to additional processing.

A system and method for imaging biological samples on multiple surfaces of a support structure are disclosed. The support structure may, for instance, be a flow cell through which a reagent fluid is allowed to flow and interact with the biological samples. Excitation radiation from at least one radiation source may be used to excite the biological samples on multiple surfaces. In this manner, fluorescent emission radiation may be generated from the biological samples and subsequently captured and detected by detection optics and at least one detector. The captured and detected fluorescent emission radiation may then be used to generate image data. This imaging of multiple surfaces may be accomplished either sequentially or simultaneously. In addition, the techniques of the present invention may be used with any type of imaging system. For instance, both epifluorescent and total internal reflection (TIR) methods may benefit from the techniques of the present invention. In addition, the biological samples imaged may be present on the surfaces of the support structure in a random special pattern and need not be at known locations in order for the imaging to be performed.

A fluorescence detecting apparatus which allows highly precise measurement of fluorescence even with minute sample amounts, which has a strong responsiveness to temperature variations, which allows simultaneous measurement of a plurality of samples, and wherein the light source and the container holder, and the container holder and the fluorescence detector, are each optically connected by optical fibers; and the optical fibers are connected to the container holder in such a manner that the sample in the container is excited for fluorescence from below the sample container held by the container holder, and that they may receive the fluorescent light which is emitted by the sample from below the sample container.

A microscope system comprising an adjusted specimen and a microscope body, wherein the adjusted specimen is dyed with molecule which has three electronic states including at least a ground state and in which an excited wavelength band from the first electron excited state to the second electron excited state overlaps a fluorescent wavelength band upon deexcitation through a fluorescence process from the first electron excited state to a vibrational level in the ground state. There is provided a novel microscope system which is enabled to condense an erase light for exciting a molecule in the first electron excited state to the second electron excited state in an excellent beam profile by using a simple, compact optical system and which has high stability and operability and an excellent super-resolution.

A system for detecting airborne agents. The system can include a laser source that provides laser pulses of at least two wavelengths, a transmitter that transmits the laser pulses, and a coupling mechanism configured to remotely couple the laser pulses between the laser source and the transmitter. The system can include a receiver receives both elastically backscattered signals from airborne agents and fluorescence signals from the airborne agents. The system can include a telescope both transmits a collimated laser beam of the laser pulse from the transmitter to a far field and receives the elastically backscattered signals and the fluorescence signals from the far field. The system can include a detection system having at least one of a backscatter optical detector that detects the elastically backscattered signals and one or more fluorescence optical detectors that detect the fluorescence signals in selected spectral band(s) from the airborne agents.

A laser scanning microscope produces molecular excitation in a target material by simultaneous absorption of three or more photons to thereby provide intrinsic three-dimensional resolution. Fluorophores having single photon absorption in the short (ultraviolet or visible) wavelength range are excited by a beam of strongly focused subpicosecond pulses of laser light of relatively long (red or infrared) wavelength range. The fluorophores absorb at about one third, one fourth or even smaller fraction of the laser wavelength to produce fluorescent images of living cells and other microscopic objects. The fluorescent emission from the fluorophores increases cubicly, quarticly or even higher power law with the excitation intensity so that by focusing the laser light, fluorescence as well as photobleaching are confined to the vicinity of the focal plane. This feature provides depth of field resolution comparable to that produced by confocal laser scanning microscopes, and in addition reduces photobleaching and phototoxicity. Scanning of the laser beam by a laser scanning microscope, allows construction of images by collecting multi-photon excited fluorescence from each point in the scanned object while still satisfying the requirement for very high excitation intensity obtained by focusing the laser beam and by pulse time compressing the beam. The focused pulses also provide three-dimensional spatially resolved photochemistry which is particularly useful in photolytic release of caged effector molecules, marking a recording medium or in laser ablation or microsurgery. This invention refers explicitly to extensions of two-photon excitation where more than two photons are absorbed per excitation in this nonlinear microscopy.

A device for detecting a presence of an analyte in a sample. The device comprises a device body configured with at least one reaction chamber configured for containing a sensor capable of producing a detectable signal when exposed to the analyte in the sample. The reaction chambers are in fluid communication with at least one sample port and at least one actuator port via a first set of microfluidic channels arranged such that application of a negative pressure to actuator port delivers fluid placed in the sample port to the reaction chambers.

This invention concerns a fluorometer preferably combined with a thermal cycler useful in biochemical protocols such as polymerase chain reaction (PCR) and DNA melting curve analysis. The present flourometer features a low heat-generating light source such as a light emitting diode (LED), having a one-to-one correspondence to each of a plurality of sample containers, such as capped PCR tubes in a standard titer tray. The flourometer of the present invention further comprises an optical path between each LED and its correspondingly positioned container, and another optical path between each flourescing sample within the positioned container and an optical signal sensing means. The instrument can be computer controlled.

A method of verifying the authenticity of a packaged product involves providing a package that includes a product, a packaging material covering at least one surface of the product, and at least two fluorescent materials, which (a) each can be disposed in or on the packaging material, (b) each can be disposed in or on at least one surface of the product, or (c) can be separated so that at least one of them is disposed in or on the packaging material and at least one of them is disposed in or on at least one surface of the product. The package is exposed to excitation radiation including one or more wavelengths in the range of from about 250 to about 400 nm, the luminescent radiation emitted by said fluorescent materials is spectroscopically detected in the wavelength range of about 300 to about 475 nm, and an intensity versus wavelength plot of the emitted radiation over at least a portion of the range of wavelengths detected is compiled. This compiled plot is compared against a previously measured, stored emitted radiation intensity versus wavelength plot from an authenticated standard so as to determine whether the packaged product is authentic.

For the high spatial resolution imaging of a structure of interest in a specimen, a substance is selected from a group of substances which have a fluorescent first state and a nonfluorescent second state; which can be converted fractionally from their first state into their second state by light which excites them into fluorescence, and which return from their second state into their first state; the specimen's structure of interest is imaged onto a sensor array, a spatial resolution limit of the imaging being greater (i.e. worse) than an average spacing between closest neighboring molecules of the substance in the specimen; the specimen is exposed to light in a region which has dimensions larger than the spatial resolution limit, fractions of the substance alternately being excited by the light to emit fluorescent light and converted into their second state, and at least 10% of the molecules of the substance that are respectively in the first state lying at a distance from their closest neighboring molecules in the first state which is greater than the spatial resolution limit; and the fluorescent light, which is spontaneously emitted by the substance from the region, is registered in a plurality of images recorded by the sensor array during continued exposure of the specimen to the light.

Nitrogen vacancies in bulk diamonds and nanodiamonds can be used to sense temperature, pressure, electromagnetic fields, and pH. Unfortunately, conventional sensing techniques use gated detection and confocal imaging, limiting the measurement sensitivity and precluding wide-field imaging. Conversely, the present sensing techniques do not require gated detection or confocal imaging and can therefore be used to image temperature, pressure, electromagnetic fields, and pH over wide fields of view. In some cases, wide-field imaging supports spatial localization of the NVs to precisions at or below the diffraction limit. Moreover, the measurement range can extend over extremely wide dynamic range at very high sensitivity.

An imaging system comprises three or more sources for providing excitation radiation of different wavelengths, an objective lens for focusing one or more of the exitation wavelengths onto a sample to produce fluorescent emission, and a mirror, configured as a geometric beamsplitter, disposed in the transmission path of the emission radiation and excitation radiation subsequent to reflection from the sample and collimation by the lens, wherein the mirror is utilized to reflect one of the collimated exitation and emission radiation such that the emission is directed to a detector and the collimated exitation is directed away from the detector.

A method for quantitatively measuring nucleic acid amplification reactions, especially the polymerase chain reaction, employing microparticles as hybridization solid phase, a probe sequence labeled with a fluorescent label and a fluorescence detection system which is based on two-photon fluorescence excitation, contacting all the amplification reaction components and the solid phase simultaneously in a closed cuvette, performing the amplification reactions in the same cuvette, focusing a two-photon exciting laser beam into the cuvette during the amplification cycles and measuring the fluorescence signal emitted by the microparticles from one particle at a time when they randomly float through the focal volume of the laser beam. The features of this invention allow a method and device for performing a fast quantitative nucleic acid amplification assay of single or multiple target sequences in a very small closed sample volume.