Matrix Compatible Buffers for Analysis of Proteins with Matrix-assisted Laser Desorption/Ionization Mass Spectrometry

Different buffers typically used in biological applications were evaluated for compatibility with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) measurements. It was found that the buffers recommended by Good and co-workers, such as HEPES and MOPS in concentrations below 50 mM do not negatively affect the MALDI-MS measurements, a fact that is in contrast to phosphate buffers. Furthermore, increased peak intensities are observed in their presence as compared with pure water or other buffers. Additionally, buffer and salt concentrations higher than 100 mM could be reduced by optimized purification methods, like drop dialysis or protein immobilization on transfer membranes.