MALDI-MS imaging of features smaller than the size of the laser beam

• DOI: 10.1016/j.jasms.2005.06.006
• Publication Date: 2005-08-11T13:12:48Z
• Authors: John C. Jurchen; Stanislav S. Ruba...; Jonathan V. Sweedler
• Keywords: MALDI imaging; Laser Ablation; Mass spectrometry imaging

The feasibility of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) imaging features smaller than the beam size has been demonstrated. method involves complete ablation MALDI matrix coating sample at each position and moving target a distance less diameter before repeating process. In limit ablation, acquiring signal from adjacent positions spaced by distances probe enhances image resolution as measured analyte only arises overlap non-ablated surface. Image acquisition demonstrated with peptide standards deposited on electron microscopy calibration grids neuropeptides originating single cells. presented MS technique enables approximately 25 microm spatial using commercial spectrometers having irregular sizes several hundred micron diameters. With appropriate sampling, is not strict barrier to attainable MALDI-MS resolution.