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Molecular histology of fixed tissues using imaging mass spectrometry (1050.4)
Author(s) -
Cornett Dale
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.1050.4
Subject(s) - mass spectrometry imaging , histology , maldi imaging , mass spectrometry , high resolution , chemistry , biomedical engineering , image resolution , computer science , chromatography , pathology , matrix assisted laser desorption/ionization , artificial intelligence , medicine , remote sensing , organic chemistry , adsorption , desorption , geology
Imaging Mass Spectrometry (IMS) yields molecular information from tissue sections that compliment traditional histology. Using the technique, distributions of label‐free proteins, lipids and small metabolites can be mapped to regions corresponding to specific histopathology. While it is widely acknowledged that fresh‐frozen tissue is preferable for IMS studies, the majority of pathology labs employ some form of fixation which often crosslinks endogenous proteins and makes them un‐detectable to IMS. Protocols for IMS analyses of Formalin‐Fixed Paraffin‐Embedded (FFPE) tissue have been described and include antigen retrieval followed by on‐tissue digestion prior to the analysis. Prior IMS studies using these protocols have yielded very low imaging resolutions, on the order of 200‐300 micron/pixel, which do not compare very well with high resolution histology. New protocols based on a commercial piezo‐driven sprayer have been developed that yield higher spatial resolution for imaging FFPE tissues. Overlaying these ion images with high resolution histology images show more comparable resolution but the need for the additional liquid‐based digestion step hinders one from achieving the 10 micron/pixel spatial resolution that can be achieved from a dry preparation. However, a secondary benefit of the protocol is that it lends itself favorably to methods for identifying structurally significant proteins from the digest peptides.