title: Imaging whole Escherichia coli bacteria by using single-particle x-ray diffraction.
abstract: We report the first experimental recording, to our knowledge, of the diffraction pattern from intact Escherichia coli bacteria using coherent x-rays with a wavelength of 2 A. By using the oversampling phasing method, a real space image at a resolution of 30 nm was directly reconstructed from the diffraction pattern. An R factor used for characterizing the quality of the reconstruction was in the range of 5%, which demonstrated the reliability of the reconstruction process. The distribution of proteins inside the bacteria labeled with manganese oxide has been identified and this distribution confirmed by fluorescence microscopy images. Compared with lens-based microscopy, this diffraction-based imaging approach can examine thicker samples, such as whole cultured cells, in three dimensions with resolution limited only by radiation damage. Looking forward, the successful recording and reconstruction of diffraction patterns from biological samples reported here represent an important step toward the potential of imaging single biomolecules at near-atomic resolution by combining single-particle diffraction with x-ray free electron lasers.
authors.affiliation: Stanford Synchrotron Radiation Laboratory, Stanford Linear Accelerator Center, Stanford University, CA 94309-0210, USA. miao@slac.stanford.edu
authors.forename: Jianwei
authors.initials: J
authors.lastname: Miao
authors.forename: Keith O
authors.initials: KO
authors.lastname: Hodgson
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Larabell
authors.forename: Mark A
authors.initials: MA
authors.lastname: LeGros
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nishino
mesh_terms: D004926:Escherichia coli / Q000648:ultrastructure*; D007091:Image Processing, Computer-Assisted; D011815:R Factors / Q000648:ultrastructure; D012680:Sensitivity and Specificity; D014961:X-Ray Diffraction / Q000379:methods