Application of mass spectrometry (MS) has recently been developed for the identification of biomarkers using pathologic samples, whereas its application using formaldehyde-fixed paraffin-embedded (FFPE) tissues remains limited. In this review, we introduce MS imaging (MSI) using FFPE tissue. This method is still challenging for peptide ionization, and various pretreatment techniques have been conducted for enhancing the ionization signal of peptides. A simple chemical pretreatment method involving heating in acetonitrile-containing buffer under pressurized conditions is introduced. Further, two-dimensional MSI data are summarized in a DM for region of interest (ROI) and hierarchical cluster analyses. These techniques enable MALDI-MSI analysis of archived pathological FFPE samples to identify new biomarkers.
Part of the book: Histology