Department of Chemistry, George Washington University, Washington D.C. 20052, United States.
Nanofabrication and Imaging Center, George Washington University, Washington D.C. 20052, United States.
Anal Chem. 2020 May 19;92(10):7289-7298. doi: 10.1021/acs.analchem.0c00936. Epub 2020 May 4.
Characterization of the metabolic heterogeneity in cell populations requires the analysis of single cells. Most current methods in single-cell analysis rely on cell manipulation, potentially altering the abundance of metabolites in individual cells. A small sample volume and the chemical diversity of metabolites are additional challenges in single-cell metabolomics. Here, we describe the combination of fiber-based laser ablation electrospray ionization (f-LAESI) with 21 T Fourier transform ion cyclotron resonance mass spectrometry (21TFTICR-MS) for single-cell metabolic profiling in plant tissue. Single plant cells infected by bacteria were selected and sampled directly from the tissue without cell manipulation through mid-infrared ablation with a fine optical fiber tip for ionization by f-LAESI. Ultrahigh performance 21T-FTICR-MS enabled the simultaneous capture of isotopic fine structures (IFSs) for 47 known and 11 unknown compounds, thus elucidating their elemental compositions from single cells and providing information on metabolic heterogeneity in the cell population.
对细胞群体的代谢异质性进行特征描述需要对单细胞进行分析。目前单细胞分析的大多数方法都依赖于细胞操作，这可能会改变单个细胞中代谢物的丰度。小样本量和代谢物的化学多样性是单细胞代谢组学的另外两个挑战。在这里，我们描述了纤维激光烧蚀电喷雾电离（f-LAESI）与 21T 傅里叶变换离子回旋共振质谱（21TFTICR-MS）相结合，用于植物组织中的单细胞代谢分析。通过中红外光纤尖端烧蚀，对受细菌感染的单细胞进行选择，并直接从组织中进行采样，而无需进行细胞操作，通过 f-LAESI 进行离子化。超高效 21T-FTICR-MS 能够同时捕获 47 种已知和 11 种未知化合物的同位素精细结构（IFS），从而从单个细胞中阐明它们的元素组成，并提供细胞群体中代谢异质性的信息。
