In situ molecular imaging of proteins in tissues using mass spectrometry

Matrix-assisted laser desorption/ionization imaging mass spectroscopy (MALDI IMS) combines parallel, high-throughput molecular analysis with location-specific information for the characterization of protein distributions directly from thin sections of intact biological tissue. This technology enables discovery in biological systems and has a unique advantages because it generates molecular-weight specific data, requires no target-specific reagents, and can sample intact large proteins of 100 kDa. The power of MALDI IMS technology lies in its capability to reliably combine protein data with specific cellular regions within tissue. It uses a laser to desorb and ionize molecules in a sample that have been cocyrstallized with a suitable matrix. It has been employed as an imaging technology in a wide variety of applications form the analysis of small molecules, such as drugs and endogenous metabolities to macromolecules.