1001 results about "Protein mass spectrometry" patented technology

Fast and highly accurate mass spectrometry-based processes for detecting a particular nucleic acid sequence in a biological sample are provided. Depending on the sequence to be detected, the processes can be used, for example, to diagnose a genetic disease or chromosomal abnormality; a predisposition to a disease or condition, infection by a pathogenic organism, or for determining identity or heredity.

The present invention is directed to a method for separating, characterizing and/or identifying microorganisms in a test sample. The method of the invention comprises an optional lysis step for lysing non-microorganism cells that may be present in a test sample, followed by a subsequent separation step. The method may be useful for the separation, characterization and/or identification of microorganisms from complex samples such as blood-containing culture media. The invention further provides for interrogation of the separated microorganism sample by mass spectrometry to produce a mass spectrum of the microorganism and characterizing and/or identifying the microorganism in the sample using the mass spectrum obtained.

Provided are methods of detecting the presence or amount of a dihydroxyvitamin in D metabolite in a sample using mass spectrometry. The methods generally comprise ionizing a dihydroxyvitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. In certain preferred embodiments the methods include immunopurifying the dihydroxyvitamin D metabolites prior to mass spectrometry. Also provided are methods to detect the presence or amount of two or more dihydroxyvitamin D metabolites in a single assay.

The invention relates to ions guided by gas flows in mass spectrometers, particularly in RF multipole systems, and to RF quadrupole mass filters and their operation with gas flows in tandem mass spectrometers. The invention provides a tandem mass spectrometer in which the RF quadrupole mass filter is operated at vacuum pressures in the medium vacuum pressure regime, utilizing a gas flow to drive the ions are through the mass filter. Vacuum pressures between 0.5 to 10 pascal are maintained in the mass filter. The mass filter may be enclosed by a narrow enclosure to guide the gas flow. The quadrupole mass filter may be followed by an RF multipole system, operated at the same vacuum pressure, serving as fragmentation cell to fragment the selected parent ions. The fragmentation cell may be enclosed by the same enclosure which already encloses the mass filter, so the ions may be driven by the same gas flow at the same vacuum pressure, greatly simplifying the required vacuum pumping system in tandem mass spectrometers. There are many other applications utilizing gas flows including supersonic gas jets in mass spectrometry.

Methods to detect, characterize, and quantitate biological samples after administration of antibody conjugates, antibody-drug conjugates of Formula I, antibodies, and fragments and metabolites thereof, by immunoaffinity bead separation, chromatography, and mass spectrometry are disclosed.

Ab-(L-D)_p  I

• • wherein
  • Ab is an antibody;
  • D is a drug moiety;
  • L is a linker covalently attached to Ab, and covalently attached to D; and
  • p is 1, 2, 3, 4, 5, 6, 7, or 8;

A method for fragmentation of analyte ions for mass spectroscopy and a system for mass spectroscopy. The method produces gas-phase analyte ions, produces gas-phase radical species separately from the analyte ions, and mixes the gas-phase analyte ions and the radical species at substantially atmospheric pressure conditions to produce fragment ions prior to introduction into a mass spectrometer. The system includes a gas-phase analyte ion source, a gas-phase radical species source separate from the gas-phase analyte ion source, a mixing region where the gas-phase analyte ions and the radical species are mixed at substantially atmospheric pressure to produce fragment ions of the analyte ions, a mass spectrometer having an entrance where at least a portion of the fragment ions are introduced into a vacuum of the mass spectrometer, and a detector in the mass spectrometer which determines a mass to charge ratio analysis of the fragment ions.

A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

A system for the analysis of polyionic molecules by mass spectrometry is provided. The polyionic molecule is attached to a charged tag which neutralizes some of the charge on the polyionic analyte. The formed adduct with a reduced net charge is then analyzed by mass spectrometry, and the determined molecular weight of the adduct can be used to calculate the molecular weight of the analyte. Mass spectrometric analyses of polynucleotides and proteins are particularly amenable to this method.

The present invention provides a multiple part capillary for use in mass analysis instruments. Specifically, a multiple part capillary comprising at least two capillary sections joined with airtight seal by a union for use in mass spectrometry (particularly with ionization sources) to transport ions between pressure regions of a mass spectrometer for analysis is described herein. Preferably, the capillary is useful to transport ions from an elevated pressure ionization source to a first vacuum region of a mass analysis system.

The invention provides a spectrum library generating method, comprising the following steps: selecting analyzed spectrograms of an experimental tandem mass spectrometry, in which information of female ionic peptide sequences, electronic charges, modified types and sites are included; removing redundant spectrograms from the analyzed spectrograms of the experimental tandem mass spectrometry to obtain representing spectrograms; dividing the female ionic peptide sequences corresponding to the representing spectrograms according to a theoretical fragmentation mode to obtain theoretical spectrograms corresponding to the representing spectrograms; combining the theoretical spectrograms and the representing spectrograms to obtain optimized spectrograms; and labeling spectral peaks for the optimized spectrograms, and utilizing the optimized spectrograms with labeled spectral peaks to generate a spectrogram database. The invention further provides a spectrogram identifying method of the tandemmass spectrometry. In the invention, in the process of matching candidate spectrograms and the spectrograms of the tandem mass spectrometry to be analyzed, mass-to-charge ratio offset of the spectralpeak possibly introduced by a potential modification is concerned so that ionic spectral peak containing modified fragments is matched, thereby achieving better modified spectrogram identifying effect.