To see molecules in 3D, scientists use X-ray crystallography – a technique in which an electron beam is fired at a crystallised sample. The patterns the electrons make as they scatter are processed to create 3D models. These help drug designers to identify novel ways to disrupt viruses or manipulate proteins . But some molecules defy this method. The mimivirus, for example, has fibres coating its shell that prevent crystallisation. Now, scientists can get a closer look using a device with lasers so intense and fast that they work even with non-crystalline samples. Like high-speed strobe lights, they fire an ultra-bright beam in super-fast pulses, so images can be collected before samples are obliterated. Here we see the pattern from a mimivirus particle, which allows scientists to glean unprecedented information about its structure. With the X-ray free-electron laser, previously hidden aspects of life can now be revealed.
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.