RESUMO
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.
Assuntos
Bacillus/química , Bacillus/ultraestrutura , Processamento de Imagem Assistida por Computador/métodos , Espectrometria de Massa de Íon Secundário/métodos , Esporos/química , Esporos/ultraestrutura , Microscopia Eletrônica de Transmissão/métodosRESUMO
Hospital administrators cannot afford to sit back, amazed at technological progress. They must be able to assess technology--both currently available and planned for the future--and they must be willing to adapt to rapid change. Assessing and planning for technology are essential for future survival.
