Binary matrix for MALDI imaging mass spectrometry of phospholipids in both ion modes.
Phospholipids (PLs) are the major building block molecules of cellular membranes. Their composition varies depending on cell types and cellular compartments. Thus, the information regarding PL distribution in tissue has important physiological and pathological significance. Recent developments in imaging mass spectrometry (IMS) have allowed complete mapping of the PL species on tissue. The IMS technique can detect different classes of PLs as well as their location information directly from tissue sections. PL head groups carry either positive and/or negative charges; therefore, IMS experiments must be conducted in both positive- and negative-ion mode to detect all types of phospholipids. Several conventional matrixes were applied on tissue for better identification. This study was conducted to enable appropriate matrix selection and optimized matrix preparation for IMS experiments in both ion modes that maximize PL identification from a single brain tissue section. The optimized matrix 2,5-dihydroxybenzoic acid (DHB) and α-cyano-4-hydroxycinnamic acid (CHCA) with a mixture of trifluoroacetic acid (TFA) and piperidine as ion pairing agents showed improved stability and consistency during both ion mode experiments and successfully identified >100 peaks of PLs determined by parent ion m/z value. Further tandem mass spectrometric analysis (MS/MS) was performed to those PLs that are anatomically important according to their distribution on rat brain tissue section.
Department of Molecular Biotechnology, WCU Program, Konkuk University, Seoul, Korea.
Selina Rahman
SR
Shanta
Li-Hua
LH
Zhou
Young Seung
YS
Park
Young Hwan
YH
Kim
Youngjun
Y
Kim
Kwang Pyo
KP
Kim
D000818:Animals; D001921:Brain / Q000378:metabolism; D003373:Coumaric Acids / Q000737:chemistry; D005841:Gentisates / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry; D057054:Molecular Imaging / Q000379:methods*; D010743:Phospholipids / Q000737:chemistry* / Q000378:metabolism*; D010880:Piperidines / Q000737:chemistry; D025341:Principal Component Analysis; D051381:Rats; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry; D014269:Trifluoroacetic Acid / Q000737:chemistry
D003373:Coumaric Acids; D005841:Gentisates; D052578:Ionic Liquids; D010743:Phospholipids; D010880:Piperidines; C007175:alpha-cyano-4-hydroxycinnamate; C032727:piperidine; D014269:Trifluoroacetic Acid; C010925:2,5-dihydroxybenzoic acid