Single-Cell Lipidomics: Characterizing and Imaging Lipids on the Surface of Individual Aplysia californica Neurons with Cluster Secondary Ion Mass Spectrometry

详细信息    查看全文

• 作者：Melissa K. Passarelli ; Andrew G. Ewing ; Nicholas Winograd
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：February 19, 2013
• 年：2013
• 卷：85
• 期：4
• 页码：2231-2238
• 全文大小：388K
• 年卷期：v.85,no.4(February 19, 2013)
• ISSN：1520-6882

文摘

Neurons isolated from Aplysia californica, an organism with a well-defined neural network, were imaged with secondary ion mass spectrometry, C₆₀-SIMS. A major lipid component of the neuronal membrane was identified as 1-hexadecyl-2-octadecenoyl-sn-glycero-3-phosphocholine [PC(16:0e/18:1)] using tandem mass spectrometry (MS/MS). The assignment was made directly off the sample surface using a C₆₀-QSTAR instrument, a prototype instrument that combines an ion source with a commercial electrospray ionization/matrix-assisted laser desorption ionization (ESI/MALDI) mass spectrometer. Normal phase liquid chromatography mass spectrometry (NP-LC鈥揗S) was used to confirm the assignment. Cholesterol and vitamin E were also identified with in situ tandem MS analyses that were compared to reference spectra obtained from purified compounds. In order to improve sensitivity on the single-cell level, the tandem MS spectrum of vitamin E reference material was used to extract and compile all the vitamin E related peaks from the cell image. The mass spectrometry images reveal heterogeneous distributions of intact lipid species, PC(16:0e/18:1), vitamin E, and cholesterol on the surface of a single neuron. The ability to detect these molecules and determine their relative distribution on the single-cell level shows that the C₆₀-QSTAR is a potential platform for studying important biochemical processes, such as neuron degeneration.