A simple desalting method for direct MALDI mass spectrometry profiling of tissue lipids

作者：Wang, Hay Yan J^*; Liu, Cheng Bin; Wu, Hsuan Wen

来源：The Journal of Lipid Research, 2011, 52(4): 840-849.

DOI：10.1194/jlr.D013060

• desalting of tissue section
• direct tissue profiling
• matrix-assisted laser desorption/ionization

Direct MALDI-mass spectrometry (MALDI-MS) profiling of tissue lipids often observes isobaric phosphatidylcholine (PC) species caused by the endogenous alkali metal ions that bias the relative abundance of tissue lipids. Fresh rat brain cryosections were washed with 70% ethanol (EtOH), water (H(2)O), or 150 mM ammonium acetate (NH(4)Ac), and the desalting effectiveness of each fluid was evaluated by MALDI-MS profiling of PC and sphingomyelin (SM) species in tissue and in the washing runoff. The results indicated that EtOH and H(2)O only partially desalted the tissue lipids, yet both substantially displaced the tissue lipids to the washing runoffs. On the other hand, NH(4)Ac effectively desalted the tissue lipids and produced a runoff containing no detectable PCs or SMs. NH(4)Ac wash also unveiled the underlying changes of PCs and SMs in the infarcted rat cortex previously masked by edema-caused increase of tissue sodium. The MS/MS of an isobaric PC in the infarcted cortex revealed the precursor change as the result of NH(4)Ac wash and confirmed the desalting effectiveness of such wash.jlr Other than desalting, NH(4)Ac wash also removes contaminants in tissue, enhances the overall spectral quality, and benefits additionally in profiling of biological molecules in tissue.-Wang, H-Y. J., C. B. Liu, and H-W. Wu. A simple desalting method for direct MALDI mass spectrometry profiling of tissue lipids. J. Lipid Res. 2011. 52: 840-849.

• 出版日期2011-4
• 单位中山大学