Jiadong Fan1, Zhibin Sun1, Jian Zhang1, Qingjie Huang2, Shengkun Yao1, Yunbing Zong1, Yoshiki Kohmura3,Tetsuya Ishikawa3, Hong Liu1, Huaidong Jiang*1Show Affiliations
- State Key Laboratory of Crystal Materials,Shandong University, Jinan 250100, China
- School of Information Science and Engineering,Shandong University, Jinan 250100, China
- RIKEN SPring-8 Center, 1-1-1, Kouto, Sayo, Hyogo 679-5148,Japan
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 nucleoid, polyβ-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 ∼1.19 g/cm3. 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.
Copyright © 2015 American Chemical Society.Go To Anal. Chem
Figure credit: Analytical Chemistry.