title: Tomography of a Cryo-immobilized Yeast Cell Using Ptychographic Coherent X-Ray Diffractive Imaging.
abstract: The structural investigation of noncrystalline, soft biological matter using x-rays is of rapidly increasing interest. Large-scale x-ray sources, such as synchrotrons and x-ray free electron lasers, are becoming ever brighter and make the study of such weakly scattering materials more feasible. Variants of coherent diffractive imaging (CDI) are particularly attractive, as the absence of an objective lens between sample and detector ensures that no x-ray photons scattered by a sample are lost in a limited-efficiency imaging system. Furthermore, the reconstructed complex image contains quantitative density information, most directly accessible through its phase, which is proportional to the projected electron density of the sample. If applied in three dimensions, CDI can thus recover the sample's electron density distribution. As the extension to three dimensions is accompanied by a considerable dose applied to the sample, cryogenic cooling is necessary to optimize the structural preservation of a unique sample in the beam. This, however, imposes considerable technical challenges on the experimental realization. Here, we show a route toward the solution of these challenges using ptychographic CDI (PCDI), a scanning variant of coherent imaging. We present an experimental demonstration of the combination of three-dimensional structure determination through PCDI with a cryogenically cooled biological sample--a budding yeast cell (Saccharomyces cerevisiae)--using hard (7.9 keV) synchrotron x-rays. This proof-of-principle demonstration in particular illustrates the potential of PCDI for highly sensitive, quantitative three-dimensional density determination of cryogenically cooled, hydrated, and unstained biological matter and paves the way to future studies of unique, nonreproducible biological cells at higher resolution.
authors.affiliation: European XFEL GmbH, Hamburg, Germany. Electronic address: klaus.giewekemeyer@xfel.eu.
authors.forename: K
authors.initials: K
authors.lastname: Giewekemeyer
authors.affiliation: European Molecular Biology Laboratory Hamburg c/o Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Hackenberg
authors.affiliation: European XFEL GmbH, Hamburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Aquila
authors.affiliation: Institut für Röntgenphysik, Georg-August-Universität Göttingen, Göttingen, Germany.
authors.forename: R N
authors.initials: RN
authors.lastname: Wilke
authors.affiliation: European Molecular Biology Laboratory Hamburg c/o Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
authors.forename: M R
authors.initials: MR
authors.lastname: Groves
authors.affiliation: European Molecular Biology Laboratory Hamburg c/o Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Jordanova
authors.affiliation: European Molecular Biology Laboratory Hamburg c/o Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
authors.forename: V S
authors.initials: VS
authors.lastname: Lamzin
authors.affiliation: European XFEL GmbH, Hamburg, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Borchers
authors.affiliation: Institute of Materials Research, Slovak Academy of Sciences, Kosice, Slovak Republic.
authors.forename: K
authors.initials: K
authors.lastname: Saksl
authors.affiliation: DESY Photon Science, Hamburg, Germany.
authors.forename: A V
authors.initials: AV
authors.lastname: Zozulya
authors.affiliation: DESY Photon Science, Hamburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Sprung
authors.affiliation: European XFEL GmbH, Hamburg, Germany. Electronic address: adrian.mancuso@xfel.eu.
authors.forename: A P
authors.initials: AP
authors.lastname: Mancuso
mesh_terms: D003198:Computer Simulation; D004583:Electrons; D005615:Freezing; D021621:Imaging, Three-Dimensional / Q000379:methods; D008962:Models, Theoretical; D017785:Photons; D011829:Radiation Dosage; D012441:Saccharomyces cerevisiae / Q000166:cytology*; D014054:Tomography / Q000379:methods*; D014961:X-Ray Diffraction / Q000295:instrumentation / Q000379:methods*; D014965:X-Rays