Imaging and Identification of Phospholipids in Mouse Liver Tissue by Matrix Assisted Laser Desorption Ionization-Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Imaging

Matrix assisted laser desorption ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS)-based mass spectrometric imaging (MSI) was applied to profile and identify phospholipid molecules in mouse liver tissues, which were cut into tissue sections (7 mu m) on a cryostat at -20 degrees C and covered with 7 g/L of alpha-cyano-4-hydroxycinnamicacid (CHCA) as matrix in 50% methanol/0. 2 trifluoroacetic acid solution. 13 phospholipid compounds, which are classified as 5 different species, phosphatidic acid (PA), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG) and phosphatidylserine (PS), were accurately identified. Their molecular weights are between 700 and 900 Da. The present results indicate that MALDI-FTICR MS-based MSI is a powerful tool to explore the distribution of disease-related molecules and drug metabolites in tissues.