Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is a unique and well developed tool for probing the protein content of
formalin-fixed, paraffin-embedded tissue (FFPE). Integral to this approach is the application of trypsin, and more recently peptide N-glycosidase F, to release tryptic peptides or N-glycans from
tissue and report localization of distinct species. This is typically done on serial or adjacent tissue sections, and there is an emerging need to understand the co-localized protein population
linked to the exact same regions of N-glycans.
This manuscript describes an approach where N-glycans are first imaged from a tissue section followed by reprocessing of the same tissue section for tryptic peptide MALDI IMS. It also describes
strategies for co-localizing peptides to target N-glycans or N-glycan regions.
This manuscript was authored by Peggi M. Angel, Anand S. Mehta, Kim Norris-Caneda, and Richard R. Drake, all from the Medical University of South Carolina, and
was first published in final edited form as: Methods Mol Biol. 2018; 1788:225-241.
doi:10.1007/7651_81 and is available in PMC (PubMed Central) 2019 January 01.
This work was supported by the National Institutes of Health/National Cancer Institute R21 CA185799 to Richard R. Drake.
MALDI Imaging Mass Spectrometry of N-glycans and Tryptic Peptides from the Same Formalin-Fixed, Paraffin-Embedded Tissue Section MALDI MSI Protocols.pdf Adobe Acrobat document [2.2 MB]