Compressed sensing electron tomography of needle-shaped biological specimens--Potential for improved reconstruction fidelity with reduced dose.

Electron tomography is an invaluable method for 3D cellular imaging. The technique is, however, limited by the specimen geometry, with a loss of resolution due to a restricted tilt range, an increase in specimen thickness with tilt, and a resultant need for subjective and time-consuming manual segmentation. Here we show that 3D reconstructions of needle-shaped biological samples exhibit isotropic resolution, facilitating improved automated segmentation and feature detection. By using scanning transmission electron tomography, with small probe convergence angles, high spatial resolution is maintained over large depths of field and across the tilt range. Moreover, the application of compressed sensing methods to the needle data demonstrates how high fidelity reconstructions may be achieved with far fewer images (and thus greatly reduced dose) than needed by conventional methods. These findings open the door to high fidelity electron tomography over critically relevant length-scales, filling an important gap between existing 3D cellular imaging techniques.The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 - ESTEEM2 (Integrated Infrastructure Initiative–I3), as well as from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC grant agreement 291522 - 3DIMAGE. B.W. and E.S. acknowledge financial support from the Deutsche Forschungsgemeinschaft (DFG) within the framework of the SPP 1570 as well as through the Cluster of Excellence “Engineering of Advanced Materials” at the Friedrich-Alexander-Universität ErlangenNürnberg. G.D. and C.D. acknowledge funding from the ERC under grant number 259619 PHOTO EM. B.W. acknowledges the Research Training Group “Disperse Systems for Electronic Applications” (DFG GEPRIS GRK 1161). R.L. acknowledges a Junior Research Fellowship from Clare College.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.ultramic.2015.10.02