320 results about "Fluorescence Spectrophotometry" patented technology

The invention provides a system and method utilizing, among other things, fluorescence spectroscopy in the ultraviolet portion of the electromagnetic spectrum to determine chemical species and concentrations. The basic measuring system includes optics, a spectrograph, a detector, and an energy source (“head” components), along with a computer and control electronics and power source capable of generating and detecting unique fluorescence signatures for individual and unique mixtures of chemical substances including, for example, prescribed and / or compounded medications, alcohol products, food types, synthetic drugs, narcotics, perfumes, liquids, and the like.

The present invention relates to a functionally integrated microanalytical system for performing fluorescence spectroscopy. A source of fluorescence-exciting radiation, typically a LED, is integrated onto a substrate along with a photodetector and, in some embodiments, an optical filter. A pixel-to-point laser lift-off process is used to effect this component integration. For those cases in which a filter is required, a thin film bandgap filter is typically used, such as CdS or CdSxSe1-x (0<x<1). A disposable microchannel containing the sample and its fluorescent tag is mounted onto the integrated assembly of LED, photodetector and (optionally) filter. This configuration of components allows the microchannel and sample to be readily removed and replaced, facilitating rapid analysis of multiple samples. Multiple LEDS, detectors and filters (if present) can also be integrated onto the same substrate, permitting multiple wavelength analysis of the sample to be performed concurrently.

The present invention relates, e.g., to a method for determining the size distribution of DNA molecules in a sample comprising cell-free nucleic acid, comprising labeling the DNA with a fluorescent dye in a stoichiometric manner, subjecting the DNA to molecular spectroscopy (e.g., cylindrical illumination confocal spectroscopy), analyzing suitable fluorescent burst parameters of the labeled DNA, and conducting single molecule DNA integrity analysis of the labeled DNA molecules in the sample. In one embodiment of the invention, the method is used as a diagnostic method for detecting cancer.

The mechanism of the UV light-induced reaction between the indole moiety of tryptophan and chloroform, and the structure of the modified tryptophan and polypeptides including such modified tryptophan residues. The excited indole moiety, which is formed upon UV light irradiation, emits a solvated electron which initiates a series of events that yield fluorescent derivatives that have CHO group covalently bound to the indole moiety. These derivatives are herein referred to as formyltryptophan, and are relatively stable. Similar reactions are observed when 5-hydroxytryptophan, 5-fluorotryptophan, or N-methylindolacetate are used in place of tryptophan, or when other haloalkanes, such as trichloracetic acid, trichlorethanol, trichlorethane, bromoform, and iodoactetate are used in place of chloroform. The derivatives can be used in a variety of applications in fluorescence spectroscopy, and for nuclear magnetic resonance, X-ray crystallography, infra-red spectroscopy, circular dicroism and mass spectroscopy. Additionally, the UV light-induced reaction between the indole moiety of tryptophan and haloalkanes can be used to prepare derivatives of tryptophan for chemical cross-linking studies of proteins and peptides.

A compact Raman and fluorescence spectroscopy system that uses a microprism or micromirror based optical structure to accomplish the introduction of excitation radiation with compactness and simplified system configuration for portable or mobile spectroscopy applications. A microprism may be glued to a surface location of a focusing lens in the system to directly receive the illumination signal without intervening optical components. Alternatively, the microprism may be simply placed in close physical proximity of the focusing lens without being glued thereto. On the other hand, a micromirror may be used instead of the microprism. The illuminating photons received by the microprism or micromirror may be directly transferred to the sample under investigation via the focusing lens. The compact system may be made portable and may further include an on-board spectrometer with or without a display unit. For chemical detecting applications, a detector (e.g., a CCD array) may also be provided along with the spectrometer.