Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland.
Anal Chem. 2011 Mar 1;83(5):1843-9. doi: 10.1021/ac102702m. Epub 2011 Feb 7.
We demonstrate a facile label-free approach for performing multidimensional chemical analysis on individual single-cell organisms by combining optical, fluorescence, and Raman microspectroscopy with matrix-free laser desorption/ionization mass spectrometry (MS). Single unicellular algae are seeded on a bare stainless steel plate and analyzed microspectroscopically. This provides information on the content and distribution of photoactive species, such as β-carotene, as well as chlorophyll and other components of the photosynthetic apparatus. Exactly the same cells are then analyzed by mass spectrometry in the negative ion mode. Phospholipid species are readily ionized by laser desorption/ionization of intact cells, without the need for an auxiliary matrix. This not only facilitates sample preparation but also preserves high spatial resolution and high sensitivity. Using this method, we were able to study the content and arrangement of proplastids and photosystem components, as well as the amounts of various phospholipid species in individual algal cells. The methodology can be used in the fundamental biological studies on these unicellular organisms, which require information on the internal structure as well as the chemical composition of individual cells.
我们展示了一种简便的无标记方法，通过将光学、荧光和拉曼显微光谱学与无基质激光解吸/电离质谱（MS）相结合，对单个单细胞生物进行多维化学分析。将单细胞藻类播种在裸露的不锈钢板上，并进行微光谱分析。这提供了有关光合作用器的内容和分布的信息，例如β-胡萝卜素以及叶绿素和其他成分。然后，通过质谱仪在负离子模式下对完全相同的细胞进行分析。通过对完整细胞进行激光解吸/电离，很容易使磷脂种类离子化，而无需辅助基质。这不仅简化了样品制备，而且保留了高空间分辨率和高灵敏度。使用这种方法，我们能够研究原质体和光合系统成分的含量和排列，以及单个藻类细胞中各种磷脂种类的含量。该方法可用于这些单细胞生物的基础生物学研究，这些研究需要有关单个细胞的内部结构以及化学成分的信息。
