Three-dimensional coherent X-ray diffraction imaging of a whole, frozen-hydrated cell

TL;DR

This paper demonstrates the first 3D cryogenic coherent diffraction imaging of a whole, frozen-hydrated cell, revealing detailed cellular morphology at nanoscale resolution, and discusses future improvements for routine high-resolution bio-imaging.

Contribution

First successful 3D cryo-CDI imaging of a whole, frozen-hydrated cell, bridging a gap in high-resolution bio-imaging techniques.

Findings

Revealed cell surface and internal morphology at 75-100 nm resolution.

Demonstrated feasibility of 3D imaging of whole cells using cryo-CDI.

Forecasted future improvements enabling tens of nanometres resolution.

Abstract

A structural understanding of whole cells in three dimensions at high spatial resolution remains a significant challenge and, in the case of X-rays, has been limited by radiation damage. By alleviating this limitation, cryogenic coherent diffraction imaging (cryo-CDI) could bridge the important resolution gap between optical and electron microscopy in bio-imaging. Here, we report for the first time 3D cryo-CDI of a whole, frozen-hydrated cell - in this case a Neospora caninum tachyzoite - using 8 keV X-rays. Our 3D reconstruction reveals the surface and internal morphology of the cell, including its complex, polarized sub-cellular architecture with a 3D resolution of ~75-100 nm, which is presently limited by the coherent X-ray flux and detector size. Given the imminent improvement in the coherent X-ray flux at the facilities worldwide, our work forecasts the possibility of routine 3D imaging of frozen-hydrated cells with spatial resolutions in the tens of nanometres.