Abstract:
An ion implantation apparatus with multiple operating modes is disclosed. The ion implantation apparatus has an ion source and an ion extraction means for forming a converging beam on AMU-non-dispersive plane therefrom. The ion implantation apparatus includes magnetic scanner prior to a magnetic analyzer for scanning the beam on the non-dispersive plane, the magnetic analyzer for selecting ions with specific mass-to-charge ratio to pass through a mass slit to project onto a substrate. A rectangular quadruple magnet is provided to collimate the scanned ion beam and fine corrections of the beam incident angles onto a target. A deceleration or acceleration system incorporating energy filtering is at downstream of the beam collimator. A two-dimensional mechanical scanning system for scanning the target is disclosed, in which a beam diagnostic means is built in.
Abstract:
Fast and highly accurate mass spectrometry-based processes for detecting particular nucleic acid molecules and mutations in the molecules are provided. In some embodiments, a process comprises: amplifying one or more target nucleic acid molecules from a biological sample; ionizing and volatilizing the amplified product; and analyzing a product by mass spectrometry to determine an observed molecular mass of the product.
Abstract:
Methods for selecting a set of SRM transitions for a peptide of interest include selecting a first transition based on sensitivity criteria and selecting at least a second transition based on selectivity criteria. A determination of the uniqueness of the first transition combined with the at least a second transition is made. When the combination of the first transition and the at least a second transition is determined to be unique to the peptide of interest, a sample containing the peptide of interest is subjected to a SRM workflow by monitoring the first transition and the second transition. Also described is an apparatus for carrying out the methods.
Abstract:
The present invention primarily relates to protein identification and can be particularly useful for bioinformaticists employing a mass spectrometry analysis. The present invention provides systems and methods to produce virtual databases, virtual database entries, or virtual amino acid sequences that can be used to improve the identification of unknown proteins and facilitate recognizing engineered proteins and distinguishing between natural and engineered genes and proteins. The present invention uses variations, such as mutation or substitution patterns, evident in and derived from known DNA, RNA, and protein sequences to predict and generate virtual DNA, RNA, and amino acid sequences that may not be represented in the current databases but that are likely to occur in nature. Substitution patterns may be derived from either the chemical, physical, and biological patterns of mutation or the derived, observable patterns of evolutionary fixation of such mutations between or within species. These virtual sequences (or databases/datafiles of such virtual sequences) contain novel, but statistically likely sequences for use in comparing to unknown proteins (peptides) for protein identification. The use of such synthetic sequences and/or databases facilitate the recognition and distinction between naturally occurring and genetically engineered DNA, RNA, and protein sequences.
Abstract:
Fast and highly accurate mass spectrometry-based processes for detecting particular nucleic acid molecules and mutations in the molecules are provided.
Abstract:
Fast and highly accurate mass spectrometry-based processes for detecting particular nucleic acid molecules and mutations in the molecules are provided.
Abstract:
Method of identification and quantitative analysis of primary and/or secondary amine(s) in a sample by mass spectrometry using stable isotope labeled internal standard is provided. Said internal standard is prepared by reaction of an authentic sample of said amine with a stable isotope labeled reagent, and is added to a sample containing said amine. Said amine in said sample is then quantitatively converted to a chemical compound of identical structure, except the stable isotope atoms, as that of said internal standard using a non-labeled reagent. Said sample is then extracted and the extract is analyzed by mass spectrometry. Identification and quantification of said amine are made from a plot of ion ratio of said converted amine to said internal standard versus amine concentration.
Abstract:
A method and apparatus for the continuous deposition of RP HPLC eluent, from isocratic or gradient elutions, on to a MALDI target using a parallel sample desalting method, allows increased sensitivity of the MALDI sample by pre-concentration of the analyte, separation of interfering contaminants from the analyte and increased dynamic range of peptide abundance that can be analyzed. The parallel processing of sample material allows greater throughput than that of manual methods.
Abstract:
A method and device for the gas-phase separation of ionic biomolecules including peptide, and protein or inorganic cluster ions or nanoparticles by ion mobility and for depositing them intact on a surface in a spatially addressable manner is described. The surface onto which the proteins are deposited can be modified for the purpose of constructing microarrays of biologically relevant materials or for promoting the growth of highly ordered protein crystals.
Abstract:
Screening methods to identify catalysts or to identify improved catalysts using mass spectrometric analysis of products of catalysis, particularly catalyst-bound intermediate products in the catalytic cycle. The methods are applicable, in particular, to screening of organometallic compounds for catalytic function. Moreover, the methods are applicable, in particular, to screening for catalysts for polymerization reactions. More specifically, the methods employ a two stage (or two step) mass spectrometric detection method in which ions formed in a first stage ionization and which are linked to catalyst performance are selected and the catalyst associated with the selected ion is identified in a second stage employing tandem mass spectrometry. In specific embodiments, the screening methods of this invention avoid explicit encoding because the identity of the catalyst is implicitly contained in the product molecular mass (typically an intermediate product), since the catalyst (or a portion thereof) remains attached to the product.