A new array-based technology for the simultaneous capture, chemical labelling and mass spectrometry analysis of peptides is presented. Isotopically labelled self-assembled monolayer (SAM) gold arrays are constructed and used simultaneously to capture and label a range of peptides. The array-immobilised, labelled peptides were released by MALDI ablation, analysed by MALDI mass spectrometry and r...

Atmospheric pressure MALDI on a Q-Exactive instrument was optimized for in-source decay and pseudo-MS3. The dependence of AP-MALDI ISD on the MALDI liquid matrix was investigated for peptides and proteins. The liquid matrices enabled long-life ISD signal, and exhibited high fragment ion yield and signal stability. Extensive a-, b-, c-, y-, and z-type fragment series were observed depending on t...

To explore the discriminatory power of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for detecting subtle differences in isogenic isolates, we tested isogenic strains of Staphylococcus aureus differing in their expression of resistance to methicillin or teicoplanin. More important changes in MALDI-TOF MS spectra were found with strains differing in ...

Enzymatically synthesized RNA samples (in vitro transcripts) were analysed by matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). Spectra of RNA up to 150 kDA (461 nucleotides) are shown. Polymerase generated sample heterogeneity and its contribution to mass resolution are discussed. A time course exonuclease digest of a 55 nt in vitro transcript was analyzed to investigat...

In the interest of a more thorough understanding of the relationship between sample deposition technique and the quality of data obtained using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, details of the electrospray (ES) process of sample deposition are investigated using a number of techniques. Sample morphology was observed with scanning electron microscopy (SEM) an...

MALDI imaging mass spectrometry is an analytical technique delivering information about the spatial distribution of molecules. MALDI-imaging is beneficial as a discovery tool, revealing molecules localized specifically to a particular feature or structure of the sample. The search for such molecules can be approached by identifying a template molecular ion with a distribution specific to the ar...

Polyanionic oligosaccharides such as dermatan sulfate (DS) and chondroitin sulfate (CS) exhibit poor ionization efficiencies and tend to undergo thermal fragmentation through the loss of SO(3) under conventional ultraviolet matrix-assisted laser desorption/ionization (UV-MALDI) conditions. A new ionic liquid matrix (ILM), a guanidinium salt of alpha-cyano-4-hydroxycinnamic acid, facilitates dir...

Herein we describe a strategy that combines peptide chips with matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) to evaluate kinase activities rapidly and semi-quantitatively. We have already shown that monolayers of alkanethiolates on gold are wellsuited as substrates for MALDI-TOF MS, and could be used to measure enzyme activities and to perform hig...

•Large-molecule decomposition products in SEIs are revealed with MALDI-TOF-MS •On-electrode chromatography is employed to assist MALDI measurements •The molecular SEI components characterized directly on the electrode surfaces •This approach can be applied a variety of battery systems The solid-electrolyte interphase (SEI) produced by electrolyte has critical impact performance. However, precis...