Hollow cone electron imaging for single particle 3D reconstruction of proteinsHollow cone electron imaging for single particle 3D reconstruction of proteins
Faculty of Sciences. Physics
Electron microscopy for materials research (EMAT)
2016London :Nature Publishing Group, 2016
Scientific reports. - London, 2011, currens
6(2016), p. 1-9
University of Antwerp
The main bottlenecks for high-resolution biological imaging in electron microscopy are radiation sensitivity and low contrast. The phase contrast at low spatial frequencies can be enhanced by using a large defocus but this strongly reduces the resolution. Recently, phase plates have been developed to enhance the contrast at small defocus but electrical charging remains a problem. Single particle cryo-electron microscopy is mostly used to minimize the radiation damage and to enhance the resolution of the 3D reconstructions but it requires averaging images of a massive number of individual particles. Here we present a new route to achieve the same goals by hollow cone dark field imaging using thermal diffuse scattered electrons giving about a 4 times contrast increase as compared to bright field imaging. We demonstrate the 3D reconstruction of a stained GroEL particle can yield about 13.5 Å resolution but using a strongly reduced number of images.