Laboratory Soft X-Ray Cryo Microscopy: Source, System and Bio Applications

Sammanfattning: Soft x-ray microscopes routinely perform high-resolution 3D imaging of biological cells in their near-native environment with short exposure times at synchrotron radiation facilities. Some laboratory-sized microscopes are aiming to make this imaging technique more accessible to a wider scientific community. However, these systems have been hampered by source instabilities hindering routine imaging of biological samples with short exposure times.This Thesis presents work performed on the Stockholm laboratory x-ray microscope. A novel heat control system has been implemented, improving the stability of the laser-produced plasma source. In combination with recent upgrades to the imaging system and an improved cryofixation method, the microscope now has the capability to routinely produce images with 10-second exposure time of cryofixed biological samples. This has allowed for tomographic imaging of cell autophagy and cell-cell interactions. Furthermore, a numerical 3D image formation model is presented as well as a novel reconstruction approach dealing with the limited depth of focus in x-ray microscopes.