A recommended and verified procedure for in situ tryptic digestion of formalin ‐fixed paraffin‐embedded tissues for analysis by matrix‐assisted laser desorption/ionization imaging mass spectrometry

AbstractMatrix ‐assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) is a molecular imaging technology uniquely capable of untargeted measurement of proteins, lipids, and metabolites while retaining spatial information about their locationin situ. This powerful combination of capabilities has the potential to bring a wealth of knowledge to the field of molecular histology. Translation of this innovative research tool into clinical laboratories requires the development of reliable sample preparation protocols for the analysis of proteins from formalin ‐fixed paraffin embedded (FFPE) tissues, the standard preservation process in clinical pathology. Although ideal for stained tissue analysis by microscopy, the FFPE process cross‐links, disrupts, or can remove proteins from the tissue, making analysis of the protein content challenging. To date, reported approaches differ widely in process and efficacy. This tutorial presents a strategy, derived from systematic testing and optimization of key parameters, for reproduciblein situ tryptic digestion of proteins in FFPE tissue and subsequent MALDI IMS analysis. The approach describes a generalized method for FFPE tissues originating from virtually any source.

Source: Journal of Mass Spectrometry - June 27, 2019 Category: Chemistry Authors: Audra M. Judd, Danielle B. Gutierrez, Jessica L. Moore, Nathan Heath Patterson, Junhai Yang, Carrie E. Romer, Jeremy L. Norris, Richard M. Caprioli Tags: SPECIAL FEATURE: TUTORIAL Source Type: research