Mds Inc.

Life Technologies Corporation

Applied Biosystems, LLC

Dh Technologies Development Pte. Ltd.

Olympus Ndt

Xunming Chen

Marvin L Vestal

Philip J Savickas

Xiangping Zhu

Stephen J Hattan

Ioannis A Papayannopoulos

An instrument and a method of detecting a target element in a multi-layer thin coating. L&#x3b1;, L&#x3b2; and L&#x3b3; x-rays are caused to be emitted from the target element (preferably lead paint) with excitation radiation. Upon detecting the emitted x-rays, an areal concentration of the target element is calculated using L&#x3b1; and L&#x3b2; intensities once, and then using the L&#x3b2; and L&#x3b3; intensities once, by reference to a single layer model; By combining the two concentrations calculated using single layer model, a more accurate concentration can be calculated for the target element in the multi-layered surface coating.

Instrument and method of measuring the concentration of a target element in a multi-layer thin coating

Accordingly, systems and methods for protein identification are provided. The present teaching provide for a system with one protein identification methodology based on one method and a second protein identification methodology based on a second protein identification methodology to interact and increase confidence in protein identification. Various embodiments employ protein identification methodologies that identify portions of a peptide. Various embodiments provide for a hypothesis generation module that can suggest modifications for the peptide based on differences between experimental and theoretical values. Various embodiments provide for an identifier module that can select one or more hypotheses from the hypothesis module as most probable. In this way, the present teachings can provide for systems and methods to combine protein identification results from multiple protein identification methodologies with the possibility of identifying modifications.

Methods and systems for discovering protein modifications and mutations

In various aspects, provided are methods for identification of the presence of modified peptides using at least in part mass spectrometric signals from metastable ions that are formed in the field free region of the analyzer. For example, in various embodiments where the modified peptides are phosphopeptides, such metastable ions can appear approximately 95 u lower than the precursor ion m/z value from which they were formed when the peptide contains a phosphate group. In various embodiments, detection of such metastable ions in a MALDI-TOF mass spectrum can identify the modified peptide. In various aspects, provided are methods for identification of the presence of modified peptides using at least in part MS/MS data from two or more of modified peptides, de-modified peptides and non-modified peptides by comparing the sequence and/or site of modification information for two or more of these three forms of a peptide.

Identification of modified peptides by mass spectrometry

The present teachings relate to a method of filtering mass spectrometer data using a variable filter window. The width of the window can depend on the mass itself and the mass defects for a family of compounds. The teachings can be used with a plurality of compounds including but not limited to peptides and can be utilized on a brood range of mass spectrometers.

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Bedford, MA, United States of America

Xunming Chen