Chemical Sciences, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
J Microsc. 2010 Jun 1;238(3):189-99. doi: 10.1111/j.1365-2818.2009.03336.x.
Preparation and sectioning of bacterial spores by focused ion beam and subsequent high resolution secondary ion mass spectrometry analytical imaging is demonstrated. Scanning transmission electron microscopy mode imaging in a scanning electron microscope is used to show that the internal structure of the bacterial spore can be preserved during focused ion beam sectioning and can be imaged without contrast staining. Ion images of the sections show that the internal elemental distributions of the sectioned spores are preserved. A rapid focused ion beam top-sectioning method is demonstrated to yield comparable ion images without the need for sample trenching and section lift-out. The lift-out and thinning method enable correlated transmission electron microscopy and high resolution secondary ion mass spectrometry analyses. The top-cutting method is preferable if only secondary ion mass spectrometry analyses are performed because this method is faster and yields more sample material for analysis; depth of useful sample material is approximately 300 nm for top-cut sections versus approximately 100 nm for electron-transparent sections.
通过聚焦离子束和随后的高分辨率二次离子质谱分析成像，展示了细菌孢子的制备和切片。扫描电子显微镜中的扫描透射电子显微镜模式成像用于表明，在聚焦离子束切片过程中可以保留细菌孢子的内部结构，并且可以在没有对比染色的情况下进行成像。切片的离子图像表明，切片孢子的内部元素分布得到保留。快速聚焦离子束顶切方法可产生可比的离子图像，而无需进行样品开槽和切片取出。如果仅进行二次离子质谱分析，则采用取出和减薄方法可实现透射电子显微镜和高分辨率二次离子质谱分析的关联。如果仅进行二次离子质谱分析，则顶切方法更可取，因为该方法更快，并且为分析提供更多的样品材料；顶切部分的有用样品材料深度约为 300nm，而电子透明部分的深度约为 100nm。
