title: Measurement of the unstained biological sample by a novel scanning electron generation X-ray microscope based on SEM.
abstract: We introduced a novel X-ray microscope system based on scanning electron microscopy using thin film, which enables the measurement of unstained biological samples without damage. An unstained yeast sample was adsorbed under a titanium (Ti)-coated silicon nitride (Si3N4) film 90 nm thick. The X-ray signal from the film was detected by an X-ray photodiode (PD) placed below the sample. With an electron beam at 2.6 kV acceleration and 6.75 nA current, the yeast image is obtained using the X-ray PD. The image is created by soft X-rays from the Ti layer. The Ti layer is effective in generating the characteristic 2.7-nm wavelength X-rays by the irradiation of electrons. Furthermore, we investigated the electron trajectory and the generation of the characteristic X-rays within the Ti-coated Si3N4 film by Monte Carlo simulation. Our system can be easily utilized to observe various unstained biological samples of cells, bacteria, and viruses.
authors.affiliation: Neuroscience Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono, Tsukuba, Ibaraki 305-8568, Japan. t-ogura@aist.go.jp
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ogura
mesh_terms: D008855:Microscopy, Electron, Scanning / Q000295:instrumentation* / Q000379:methods*; D009010:Monte Carlo Method; D012441:Saccharomyces cerevisiae / Q000648:ultrastructure; D017655:Silicon Compounds / Q000737:chemistry; D014025:Titanium / Q000737:chemistry; D014962:X-Ray Film; D014965:X-Rays
chemical_list: D017655:Silicon Compounds; D014025:Titanium; C032734:silicon nitride