标题：Quantitative Imaging of Single Unstained Magnetotactic Bacteria by Coherent X-ray Diffraction Microscopy
作者：Fan, Jiadong;Sun, Zhibin;Zhang, Jian;Huang, Qingjie;Yao, Shengkun;Zong, Yunbing;Kohmura, Yoshiki;Ishikawa, Tetsuya;Liu, Hong;Jia
作者机构：[Fan, J] State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China;[ Sun, Z] State Key Laboratory of Crystal Materials, Sha 更多
通讯作者地址：[Jiang, HD]Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Peoples R China.
摘要：Novel coherent diffraction microscopy provides a powerful lensless imaging method to obtain a better understanding of the microorganism at the nanoscale. Here we demonstrated quantitative imaging of intact unstained magnetotactic bacteria using coherent X-ray diffraction microscopy combined with an iterative phase retrieval algorithm Although the signal-to-noise ratio of the X-ray diffraction pattern from single magnetotactic bacterium is weak due to low-scattering ability of biomaterials, an 18.6 nm half-period resolution of reconstructed image was achieved by using a hybrid input-output phase retrieval algorithm. On the basis of the quantitative reconstructed images, the morphology and some intracellular structures, such as nudeoid, poly beta-hydroxybutyrate granules, and magnetosomes, were identified, which were also confirmed by scanning electron microscopy and energy dispersive spectroscopy. With the benefit from the quantifiability of coherent diffraction imaging, for the first time to our knowledge, an average density of magnetotactic bacteria was calculated to be similar to 1.19 g/cm(3). This technique has a wide range of applications, especially in quantitative imaging of low-scattering biomaterials and multicomponent materials at nanoscale resolution. Combined with the cryogenic technique or X-ray free electron lasers, the method could image cells in a hydrated condition, which helps to maintain their natural structure.