Differentiation of bacteria using protein profiles from matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry is demonstrated as a means for rapidly differentiating bacteria based upon their water‐soluble‐protein profiles. The procedure involves release of cell contents by breaking cell membranes using a sonication method, and is performed with minimal sample preparation. Minimal purification of cell contents is required for the procedure. Protein profile signals obtained are found to be enhanced greatly by the use of a Nafion substrate.