Premium
Identification of proteins directly from tissue: in situ tryptic digestions coupled with imaging mass spectrometry
Author(s) -
Groseclose M. Reid,
Andersson Malin,
Hardesty William M.,
Caprioli Richard M.
Publication year - 2007
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1177
Subject(s) - chemistry , trypsin , mass spectrometry , matrix assisted laser desorption/ionization , chromatography , mass spectrometry imaging , maldi imaging , in situ , sample preparation , peptide mass fingerprinting , protein mass spectrometry , digestion (alchemy) , proteolysis , proteomics , biochemistry , tandem mass spectrometry , desorption , enzyme , organic chemistry , adsorption , gene
A novel method for on‐tissue identification of proteins in spatially discrete regions is described using tryptic digestion followed by matrix‐assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) with MS/MS analysis. IMS is first used to reveal the protein and peptide spatial distribution in a tissue section and then a serial section is robotically spotted with small volumes of trypsin solution to carry out in situ protease digestion. After hydrolysis, 2,5‐Dihydroxybenzoic acid (DHB) matrix solution is applied to the digested spots, with subsequent analysis by IMS to reveal the spatial distribution of the various tryptic fragments. Sequence determination of the tryptic fragments is performed using on‐tissue MALDI MS/MS analysis directly from the individual digest spots. This protocol enables protein identification directly from tissue while preserving the spatial integrity of the tissue sample. The procedure is demonstrated with the identification of several proteins in the coronal sections of a rat brain. Copyright © 2007 John Wiley & Sons, Ltd.