Mass Spectrometry Imaging, Laser Capture Microdissection, and LC-MS/MS of the Same Tissue Section

Mass
spectrometry imaging (MSI) is able to simultaneously record the distributions
of hundreds of molecules directly from tissue. Rapid direct tissue
analysis is essential for MSI in order to maintain spatial localization
and acceptable measurement times. The absence of an explicit analyte
separation/purification step means MSI lacks the depth of coverage
of LC-MS/MS. In this work, we demonstrate how atmospheric pressure
MALDI-MSI enables the same tissue section to be first analyzed by
MSI, to identify regions of interest that exhibit distinct molecular
signatures, followed by localized proteomics analysis using laser
capture microdissection isolation and LC-MS/MS.