Almeida Reinaldo, Berzina Zane, Arnspang Eva C, Baumgart Jan, Vogt Johannes, Nitsch Robert, Ejsing Christer S
VILLUM Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark , Odense, Denmark.
Anal Chem. 2015 Feb 3;87(3):1749-56. doi: 10.1021/ac503627z. Epub 2015 Jan 15.
Here we describe a novel surface sampling technique termed pressurized liquid extraction surface analysis (PLESA), which in combination with a dedicated high-resolution shotgun lipidomics routine enables both quantification and in-depth structural characterization of molecular lipid species extracted directly from tissue sections. PLESA uses a sealed and pressurized sampling probe that enables the use of chloroform-containing extraction solvents for efficient in situ lipid microextraction with a spatial resolution of 400 μm. Quantification of lipid species is achieved by the inclusion of internal lipid standards in the extraction solvent. The analysis of lipid microextracts by nanoelectrospray ionization provides long-lasting ion spray which in conjunction with a hybrid ion trap-orbitrap mass spectrometer enables identification and quantification of molecular lipid species using a method with successive polarity shifting, high-resolution Fourier transform mass spectrometry (FTMS), and fragmentation analysis. We benchmarked the performance of the PLESA approach for in-depth lipidome analysis by comparing it to conventional lipid extraction of excised tissue homogenates and by mapping the spatial distribution and molar abundance of 170 molecular lipid species across different anatomical mouse brain regions.
在此，我们描述了一种名为加压液体萃取表面分析（PLESA）的新型表面采样技术，该技术与专门的高分辨率鸟枪法脂质组学程序相结合，能够对直接从组织切片中提取的分子脂质种类进行定量和深入的结构表征。PLESA使用密封且加压的采样探头，可使用含氯仿的萃取溶剂进行高效的原位脂质微萃取，空间分辨率为400μm。脂质种类的定量通过在萃取溶剂中加入内标脂质来实现。通过纳米电喷雾电离对脂质微萃取物进行分析，可提供持久的离子喷雾，结合混合离子阱-轨道阱质谱仪，能够使用连续极性转换、高分辨率傅里叶变换质谱（FTMS）和碎片分析的方法对分子脂质种类进行鉴定和定量。我们通过将PLESA方法与切除组织匀浆的传统脂质提取方法进行比较，并绘制170种分子脂质种类在不同解剖学小鼠脑区的空间分布和摩尔丰度，对其进行深入脂质组分析的性能进行了基准测试。
