Phospholipids direct tissue analysis

Jackson S, Wang H, Woods A, Ugarov M, Egan T, Schultz A (2005) Direct tissue analysis of phospholipids in rat brain using MALDI-TOFMS and MALDI-Ion mobility-TOFMS. J Am Soc Mass Spectrom 16 133-138. doi 10.1016/j.jasms.2004.10.002... 

As a practical example, when a mouse brain section to which 2,5-dihydroxybenzoic acid (DHB) has been applied as a matrix is subjected directly to MS in positive ion-detection conditions, strong peaks which are mainly derived from phospholipids were observed in mass region of 700 < m/z < 900 [8] on the other hand, signals derived from proteins, meanwhile, are scarcely detected at m/z > 3000 [9].This is because phospholipids ionize much more efficiently than proteins, and they, on the other hand, suppress protein/peptide ionization. Therefore, for detecting/imaging proteins and peptides, removal of such lipids improves the sensitivity for proteins analysis. To this end, tissue sections should be rinsed with organic solvent, to remove lipids from tissue samples [9-11]. 

---