Three sample preparation strategies commonly employed in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOFMS) of whole bacterial cells were investigated for the detection of high mass signals; these included the dried droplet, the seed-layer/two-layer, and the bottom-layer methods. Different sample preparation approaches favoured the detection of high- or low-mass protein...

This study examines the features and limitations of direct Matrix-Assisted Laser Desorption-Ionisation (MALDI) mass-spectrometry profiling of bacterial cells for investigating a microbial population. The optimal laboratory protocol, including crude bacteria lyses by a solution of 50% acetonitrile, 2.5% trifluoroacetic acid, and using α-cyano-4-hydroxy cinnamic acid as the MALDI matrix, has been...

MALDI imaging allows the creation of a "molecular image" of a tissue slice. This image is reconstructed from the ion abundances in spectra obtained while rastering the laser over the tissue. These images can then be correlated with tissue histology to detect potential biomarkers of, for example, aberrant cell types. MALDI, however, is known to have problems with ion suppression, making it diffi...

Argentinated peptide ions are formed in abundance under matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) conditions in the presence of Ag+ ions. These argentinated peptide ions are fragmented facilely under MALDI-MS/MS conditions to yield [b(n) + OH + Ag]+, [b(n) - H + Ag]+ and [a(n) - H + Ag]+ ions that are indicative of the C-terminal sequence. These observations paral...

Sensitivity and detection limit enhancements are obtained for peptides by performing high repetition rate (150 Hz) matrix-assisted laser desorption/ionization (MALDI) coupled with ion mobility-time-of-flight mass spectrometry. Absolute limits of detection (3sigma) for model peptides are on the order of 0.1 fmol of peptide deposited and represent a factor of 40-60 improvement over data obtained ...

A comparison of a matrix-assisted laser desorption ionization-time of flight mass spectrometric (MALDI-TOF MS) meropenem hydrolysis assay with the Carba NP test showed that both methods exhibited low sensitivity (approximately 76%), mainly due to the false-negative results obtained with OXA-48-type producers. The addition of NH4HCO3 to the reaction buffer for the MALDI-TOF MS assay dramatically...

Identification of novel tumor-related antigens and autoantibodies will lead to early diagnosis of cancer and the development of more effective immunotherapies. The purpose of this study was to identify novel tumor antigens from the gastric cancer cell lines MkN-1, MkN-45 and KATOIII, and their related autoantibodies in sera of patients with gastric cancer using a proteomics-based approach. Prot...

Glycomics is a developing field that provides structural information on complex populations of glycans isolated from tissues, cells and organs. Strategies employing matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) are central to glycomic analysis. Current MALDI-based glycomic strategies are capable of efficiently analyzing glycoprotein and glycosphingo...

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) can be used as a method for the rapid identification of microorganisms. This study evaluated the Bruker Biotyper (MALDI-TOF MS) system for the identification of clinically relevant Gram-positive organisms. We tested 239 aerobic Gram-positive organisms isolated from clinical specimens. We evaluated 4 dire...

INTRODUCTION Gordonia spp. infections are uncommon. However, a few clinical cases have been reported in the literature, particularly those involving immunocompromised hosts. Advanced microbiology diagnosis techniques, such as matrix-assisted laser desorption ionization-time of flight MS (MALDI-TOF MS), have been recently introduced in clinical microbiology laboratories in order to improve micro...