Secondary Ion MS Imaging of Lipids in Picoliter Vials with a Buckminsterfullerene Ion Source

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• 作者：Sara G. Ostrowski ; Christopher Szakal ; Joseph Kozole ; Thomas P. Roddy ; Jiyun Xu ; Andrew G. Ewing ; and Nicholas Winograd
• 刊名：Analytical Chemistry
• 出版年：2005
• 出版时间：October 1, 2005
• 年：2005
• 卷：77
• 期：19
• 页码：6190 - 6196
• 全文大小：435K
• 年卷期：v.77,no.19(October 1, 2005)
• ISSN：1520-6882

文摘

Investigation of the spatial distribution of lipids in cellmembranes can lead to an improved understanding of therole of lipids in biological function and disease. Time-of-flight secondary ion mass spectrometry is capable ofmolecule-specific imaging of biological molecules acrosssingle cells and has demonstrated potential for examiningthe functional segregation of lipids in cell membranes. Inthis paper, standard SIMS spectra are analyzed for phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, phosphatidylinositol, cholesterol, and sulfatide.Importantly, each of the lipids result in signature massspectral peaks that allow them to be identified. Thesesignature peaks are also useful for imaging experimentsand are utilized here to simultaneously image lipids on amicrometer scale in picoliter vials. Because the lowsecondary ion signal achieved for lipids from an atomicprimary ion source makes cell-imaging experiments challenging, improving signal with cluster primary ion sourcesis of interest. Here, we compare the secondary ion yieldfor seven lipids using atomic (Ga⁺ or In⁺) ion sources anda buckminsterfullerene (C₆₀⁺) primary ion source. A 40-1000-fold improvement in signal is found with C₆₀⁺relative to the other two ion sources, indicating greatpromise for future cellular imaging applications using theC₆₀⁺ probe.