NanoSIMS imaging ofBacillusspores sectioned by focused ion beam

Abstract

SummaryPreparation 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 liftout 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 ∼300 nm for top-cut sections versus ∼100 nm for electron-transparent sections.

NanoSIMS as a tool for characterizing soil model compounds and organomineral associations in artificial soils

“…NanoSIMS has been mainly applied in material science (Lozano-Perez et al 2008), geology and cosmochemistry (Messenger et al 2003;Sano et al 2005;Floss et al 2006), biology, and especially microbiology (Peteranderl and Lechene 2004;McMahon et al 2006b;Clode et al 2007;Li et al 2008;Weber et al 2010), but recently, it also expanded into soil science, mainly by experiments using isotopic tracer techniques (Herrmann et al 2007a;Clode et al 2009;Kögel-Knabner et al 2010). A first review about the great potential of NanoSIMS for soil science is given by Herrmann et al (2007b).…”

Impact of substrate surface scratches on the laser damage resistance of multilayer coatings

“…[12][13] The structural feature of the defective multilayer used for the simulation was revealed by cross sectioning the region where the substrate scratch resides. The cross-sectional view of the interested region was achieved by trenching the coating materials at a 45 angle with respect to the surface normal using a focused beam of gallium ions [14] in a high vacuum chamber. Because of the dielectric nature of the multilayer, the sample surface was coated with a thin layer of Au before cutting to prevent sample charging.…”

NanoSIMS Analysis of Bacillus Spores for Forensics

“…Since the anthrax letter attacks in the United States in the fall of 2001, there has been increased interest in physical and chemical characterization of bacterial spores [1][2][3][4][5][6][7][8][9][10][11]. While molecular methods are powerful tools for identifying genetic differences, other methods may be able to differentiate genetically identical samples based on physical and chemical properties, as well as provide complimentary information, such as methods of production and approximate date of production.…”

“…The directly imaged samples are sectioned to present a flat surface for analysis. We use focused ion beam (FIB) milling to top-cut individual spores to create flat surfaces for NanoSIMS analysis [11]. Depth profiling can be used on whole spores, which are consumed in the process of analysis [9].…”