Thermo Finnigan LLC

Oxoid Limited

Oxiod Limited

James L Stephenson, Jr

Ping F Yip

John E P Syka

Oksana Gvozdyak

Iain C Mylchreest

August A Specht

Clay Campbell

Ian D Jardine

Roger Grist

Helene L Cardasis

Scott R Kronewitter

A method comprises: (1) making an extract of a biological sample; (2) repeatedly: (a) choosing a respective one of a plurality of pre-determined protein or polypeptide analyte compounds; (b) introducing a portion of the extract into an electrospray ionization source, thereby generating positive ions comprising a plurality of ion species; (c) isolating a plurality of subsets of the ion species comprising respective mass-to-charge (m/z) ratio ranges, each range including an m/z ratio corresponding to a respective protonation state of the chosen compound; (d) reacting the isolated plurality of subsets of first-generation ion species with proton transfer reaction reagent anions for a pre-determined time duration; (e) generating a mass spectrum of the product ion species; and (g) identifying either the presence or absence of the compound based on the mass spectrum; and (3) identifying the presence or absence of the microorganism within the sample based on analytes present.

Methods for mass spectrometry of mixtures of proteins or polypeptides using proton transfer reaction

The present disclosure establishes new dissociation parameters that may be used to determine the collision energy (CE) needed to achieve a desired extent of dissociation for a given analyte precursor ion using collision cell type collision-induced dissociation. This selection is based solely on the analyte precursor ion's molecular weight, MW, and charge state, z. Metrics are proposed that may be used as a parameter for the 'extent of dissociation', and then predictive models are developed of the CEs required to achieve a range of values for each metric. Each model is a simple smooth function of only MW and z of the precursor ion. Coupled with a real-time spectral deconvolution (m/z to mass) algorithm, methods in accordance with the invention enable control over the extent of dissociation through automated, real-time selection of collision energy in a precursor-dependent manner.

Automated determination of mass spectrometer collision energy

An embodiment of a method for real time material identification is described that comprises determining an approximate mass value for an unknown material from spectral information derived from mass spectral analysis of the unknown material; retrieving profile models that correspond to a known material from a data structure using the approximate mass value; fitting a sample profile for the unknown material from the spectral information to the profile models to generate a fit score for each fit, wherein the lowest fit score corresponds to the best fit; calculating a mass value from the best fitting profile model and the sample profile.

System and method for real-time isotope identification

A method for mass spectral analysis of a sample containing a plurality of biomolecule species comprises: (a) mass analyzing a plurality of first-generation ion species generated from a sample portion; (b) automatically recognizing, for each of at least one biomolecule species, a respective subset of m/z ratios corresponding to respective first-generation ion species generated from the each biomolecule species; (c) selecting, from each recognized subset, a single representative m/z ratio; (d) isolating a sub-population of ions having each representative m/z ratio from ions having other m/z ratios; and (e) fragmenting each isolated sub-population of ions so as to generate second-generation ion species.

Methods for data-dependent mass spectrometry of mixed intact protein analytes

Methods and systems for identification of microorganisms either after isolation from a culture or directly from a sample. The methods and systems are configured to identify microorganisms based on the characterization of proteins of the microorganisms via high-resolution/mass accuracy single-stage (MS) or multi-stage (MS) mass spectrometry. Included herein are also discussion of targeted detection and evaluation of virulence factors, antibiotic resistance markers, antibiotic susceptibility markers, typing, or other characteristics using a method applicable to substantially all microorganisms and high-resolution/mass accuracy single-stage (MS) or multi-stage (MS) mass spectrometry.

Methods for microbial identification by mass spectrometry

Applications of ion-ion reaction chemistry are disclosed in which proton transfer reactions (PTR) and real-time data analysis methods are used to (1) simplify complex mixture analysis of samples introduced into a mass spectrometer, and (2) improve resolution and sensitivity for the analysis of large proteins in excess of 50 kDa by removing charge and reducing the collisional cross section.

Methods for top-down multiplexed mass spectral analysis of mixtures of proteins or polypeptides

Applications of ion-ion reaction chemistry are disclosed in which proton transfer reactions (PTR) are used to (1) simplify complex mixture analysis of samples introduced into a mass spectrometer, and (2) improve resolution and sensitivity for the analysis of large proteins in excess of 50 kDa by removing charge and reducing the collisional cross section.

Growing community of inventors

Raleigh, NC, United States of America

James L Stephenson, Jr