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: 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: 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: 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 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: A mass spectrometric method for sequencing nucleic acids using RNA polymerases, including DNA-dependent and RNA-dependent RNA polymerases, is provided. The methods use a modified Sanger sequencing strategy in which RNA polymerase is used to generate a set of nested RNA transcripts obtained by base-specific chain termination. These are analyzed by mass spectrometry. A method of identifying transcriptional terminator sequences or attenuator sequences is also provided.

Abstract: Novel compositions comprised of at least one bead conjugated to a solid support and further conjugated to at least one nucleic acid and preferred methods for making the novel compositions are described. As compared to "flat" surfaces, beads linked to a solid support provide an increased surface area for immobilization of nucleic acids. Furthermore, by selecting a bead with the desired functionality, a practitioner can select a functionalization chemistry for immobilizing nucleic acids, which is different from the chemistry of the solid support.

Abstract: Novel compositions comprised of at least one bead conjugated to a solid support and further conjugated to at least one nucleic acid and preferred methods for making the novel compositions are described. As compared to "flat" surfaces, beads linked to a solid support provide an increased surface area for immobilization of nucleic acids. Furthermore, by selecting a bead with the desired functionality, a practitioner can select a functionalization chemistry for immobilizing nucleic acids, which is different from the chemistry of the solid support.

Abstract: Novel compositions comprised of at least one bead conjugated to a solid support and further conjugated to at least one nucleic acid and preferred methods for making the novel compositions are described. As compared to “flat” surfaces, beads linked to a solid support provide an increased surface area for immobilization of nucleic acids. Furthermore, by selecting a bead with the desired functionality, a practitioner can select a functionalization chemistry for immobilizing nucleic acids, which is different from the chemistry of the solid support.

Abstract: Novel compositions comprised of at least one bead conjugated to a solid support and further conjugated to at least one nucleic acid and preferred methods for making the novel compositions are described. As compared to “flat” surfaces, beads linked to a solid support provide an increased surface area for immobilization of nucleic acids. Furthermore, by selecting a bead with the desired functionality, a practitioner can select a functionalization chemistry for immobilizing nucleic acids, which is different from the chemistry of the solid support.