Identification of Proteins by MALDI-TOF MS

Abstract

Matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) produces gas-phase protonated ions by excitation of the sample molecules from the energy of a laser transferred via an ultraviolet (UV) light-absorbing matrix. The matrix is a conjugated organic compound (normally a weak organic acid). Different MALDI matrix compounds are optimal for particular biomolecules, and maximally absorb light at the wavelength of the laser, typically a nitrogen laser of 337 nm (see Note 1).