Abstract: Described here is a detector for measuring heavy mass ions with high sensitivity and low saturation for time-of-flight mass spectrometry and a detector housing for selecting between multiple detectors.

Abstract: Described here is a detector for measuring heavy mass ions with high sensitivity and low saturation for time-of-flight mass spectrometry and a detector housing for selecting between multiple detectors. It relates to sensitive measuring methods of large masses in the range of about ten thousand to a few million atomic mass units. Specifically it relates to a conversion dynode in a specifically insolated geometry followed by a discrete dynode secondary electron multiplier specifically modified to decrease electron saturation and electronic ringing. Conversion dynode detectors have been used before for time-of-flight mass spectrometry and compared to direct detection with electron multipliers they exhibit superior sensitivity for high-mass, slow-moving macromolecular ions.

Abstract: Provided are methods for detecting a target nucleic acid in a biological sample using RNA amplification. In an embodiment, provided is a method that comprises (a) amplifying a target nucleic acid, or portion thereof, using a primer comprising a sequence that is complementary to a polynucleotide sequence in the target nucleic acid, or a complement thereof, and a sequence that encodes an RNA polymerase promoter; (b) synthesizing RNA using an RNA polymerase that recognizes the promoter; and (c) detecting the presence or absence of the resulting RNA using mass spectrometry thereby detecting the presence or absence of the target nucleic acid in the biological sample.

Abstract: 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.

Abstract: 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.

Abstract: Matrix assisted laser desorption/ionization (MALDI) is performed in a manner that thermalizes large analyte ions in a plume of desorbed material for spectroscopic analysis. The thermalized ions have a low or zero mean velocity and are presented at a well-defined instant in time, reducing artifacts and sharpening the spectral peaks. In one embodiment the light is delivered to a matrix or sample holder having a cover, baffle or compartment. The baffle or compartment impedes or contains a plume of desorbed material and the analyte undergoes collisions to lower its mean velocity and directionality. Thus “thermalized” the analyte ions are passed to a mass analysis instrument.

Abstract: Mass spectrometry of large nucleic acids by infrared Matrix-Assisted Laser Desorption/Ionization (MALDI) using a liquid matrix is reported.

Abstract: Mass spectrometry of large nucleic acids by infrared Matrix-Assisted Laser Desorption/Ionization (MALDI) using a liquid matrix is reported.

Abstract: Mass spectrometry of large nucleic acids by infrared Matrix-Assisted Laser Desorption/Ionization (MALDI) using a liquid matrix is reported.

Abstract: Mixtures containing a biological macromolecule, such as a nucleic acid molecule or a polypeptide, and a liquid matrix, which absorbs infrared (IR) radiation, are provided. These mixtures are useful for analysis of the biological macromolecule by IR matrix assisted laser desorption/ionization (IR-MALDI) mass spectrometry. Also provided are processes for analyzing a biological macromolecule using IR-MALDI mass spectrometry. For example, processes for detecting the presence or identity of a biological macromolecule in a sample, or for sequencing a biological macromolecule are provided.

Abstract: Matrix assisted laser desorption/ionization (MALDI) is performed in a manner that thermalizes large analyte ions in a plume of desorbed material for spectroscopic analysis. The thermalized ions have a low or zero mean velocity and are presented at a well-defined instant in time, reducing artifacts and sharpening the spectral peaks. In one embodiment the light is delivered to a matrix or sample holder having a cover, baffle or compartment. The baffle or compartment impedes or contains a plume of desorbed material and the analyte undergoes collisions to lower its mean velocity and directionality. Thus “thermalized” the analyte ions are passed to a mass analysis instrument.

Abstract: Matrix assisted laser desorption/ionization is performed,in a manner to thermalize large analyte ions in a plume of desorbed material for spectroscopic analysis. The thermalized ions have a low or zero mean velocity and are presented at a well-defined instant in time, reducing artifacts and sharpening the spectral peaks. In one embodiment the light is delivered to a matrix or sample holder having a cover, baffle or compartment. The baffle or compartment impedes or contains a plume of desorbed material and the analyte undergoes collisions to lower its mean velocity and directionality. Thus “thermalized” the analyte ions are passed to a mass analysis instrument. In a preferred embodiment an optical fiber butts up against a thin transparent plate on which the specimen resides, with the matrix side in a vacuum acceleration chamber. A mechanical stage moves the specimen in both the x- and y-directions to select a point on the specimen which is to receive the radiation.

Abstract: Matrix assisted laser desorption/ionization is performed in a manner to thermalize large analyte ions in a plume of desorbed material for spectroscopic analysis. The thermalized ions have a low or zero mean velocity and are presented at a well-defined instant in time, reducing artifacts and sharpening the spectral peaks. In one embodiment the light is delivered to a matrix or sample holder having a cover, baffle or compartment. The baffle or compartment impedes or contains a plume of desorbed material and the analyte undergoes collisions to lower its mean velocity and directionality. Thus “thermalized” the analyte ions are passed to a mass analysis instrument. In a preferred embodiment an optical fiber butts up against a thin transparent plate on which the specimen resides, with the matrix side in a vacuum acceleration chamber. A mechanical stage moves the specimen in both the x- and y- directions to select a point on the specimen which is to receive the radiation.

Abstract: Mass spectrometry of large nucleic acids by infrared Matrix-Assisted Laser Desorption/Ionization (MALDI) using a liquid matrix is reported.

Abstract: Matrix assisted laser desorption/ionization is performed in a manner to thermalize large analyte ions in a plume of desorbed material for spectroscopic analysis. The thermalized ions have a low or zero mean velocity and are presented at a well-defined instant in time, reducing artifacts and sharpening the spectral peaks. In one embodiment the light is delivered to a matrix or sample holder having a cover, baffle or compartment. The baffle or compartment impedes or contains a plume of desorbed material and the analyte undergoes collisions to lower its mean velocity and directionality. Thus "thermalized" the analyte ions are passed to a mass analysis instrument. In a preferred embodiment an optical fiber butts up against a thin transparent plate on which the specimen resides, with the matrix side in a vacuum acceleration chamber. A mechanical stage moves the specimen in both the x- and y-directions to select a point on the specimen which is to receive the radiation.

Abstract: Matrix assisted laser desorption/ionization is performed in a manner to thermalize large analyte ions in a plume of desorbed material for spectroscopic analysis. The thermalized ions have a low or zero mean velocity and are presented at a well-defined instant in time, reducing artifacts and sharpening the spectral peaks. In one embodiment the light is delivered to a matrix or sample holder having a cover, baffle or compartment. The baffle or compartment impedes or contains a plume of desorbed material and the analyte undergoes collisions to lower its mean velocity and directionality. Thus "thermalized" the analyte ions are passed to a mass analysis instrument. In a preferred embodiment an optical fiber butts up against a thin transparent plate on which the specimen resides, with the matrix side in a vacuum acceleration chamber. A mechanical stage moves the specimen in both the x- and y-directions to select a point on the specimen which is to receive the radiation.

Abstract: Detector device for analyzing ions of high mass using a time-of-flight (TOF) analytical method, consisting of a mass spectrometer 1, accelerating electrodes 2 and a magnetic field and/or electric field, all of which serves to deflect secondary ions 5 emerging from a first conversion dynode 8, so that the secondary ions impinge according to polarity on a second 7 and third 7' conversion dynode.

Abstract: The invention relates to a process for the laser desorption of analyte molecular ions, especially of biomolecules, from a specimen. The object of the invention is to improve a process of this type in such a way that intact desorption of biomolecules, preferably of large molecular mass, is also possible with a laser. This is achieved by using laser light of a wavelength of about 300 nm or greater than 300 nm and using a matrix which is able to absorb in the selected wavelength range.

Abstract: A method and apparatus for analyzing a sample comprising the steps of irradiating a selected area of the sample with a first burst of laser energy to vaporize the sample, condensing the vaporized sample on the surface of an intermediate carrier and analyzing the condensed sample material deposited on the intermediate carrier.

Abstract: An apparatus for analyzing a sample by electromagnetic irradiation includes a vacuum chamber, a support for holding the sample in the vacuum chamber, an arrangement for irradiating the sample with an electromagnetic beam, a mass analyzer disposed in the vacuum chamber, an arrangement for extracting particles from the sample and introducing them into the mass analyzer and a layer of conductive material situated in the vicinity of support in the zone of the sample.