Biological Laboratory X-Ray Microscopy

摘要

Zone-plate-based soft x-ray microscopes operating in the water window allow high-resolution and high-contrast imagingof intact cells in their near-native state. Laboratory-source-based x-ray microscopes are an important complement to theaccelerator-based instruments, providing high accessibility and allowing close integration with other cell-biologicaltechniques. Here we present recent biological applications using the Stockholm laboratory water-window x-raymicroscope, which is based on a liquid-nitrogen-jet laser-plasma source. Technical improvements to the microscope inthe last few years have resulted in increased x-ray flux at the sample and significantly improved stability and reliability.In addition to this, vibrations in key components have been measured, analyzed and reduced to improve the resolution to25 nm half-period. The biological applications include monitoring the development of carbon-dense vesicles in starvinghuman embryonic kidney cells (HEK293T), imaging the interaction between natural killer (NK) cells and HEK293T targetcells, and most recently studying a newly discovered giant DNA virus and the process of viral replication inside a hostamoeba. All biological imaging was done on cryo-frozen hydrated samples in 2D and in some cases 3D.