Wednesday, 25 March 2015

The first X-ray portraits of living bacteria


Researchers have captured the first X-ray portraits of living bacteria. This milestone is a first step toward possible X-ray explorations of the molecular machinery at work in viral infections, cell division, photosynthesis and other processes that are important to biology, human health and our environment.

The experiment took place at SLAC's Linac Coherent Light Source (LCLS) X-ray laser, a DOE Office of Science User Facility. The experiment focused on cyanobacteria, or blue-green algae. The cyanobacteria were passed into an ultrabright, rapid-fire LCLS X-ray pulses, producing diffraction patterns recorded by detectors.

The diffraction patterns preserved details of the living cyanobacteria that were compiled to reconstruct 2-D images. Researchers said it should be possible to produce 3-D images of some samples using the same technique.

The technique works with live bacteria and requires no special treatment of the samples before imaging. Other high-resolution imaging methods may require special dyes to increase the contrast in images, or work only on dead or frozen samples.

The technique can capture about 100 images per second, amassing many millions of high-resolution X-ray images in a single day. This speed allows sorting and analysis of the inner structure and activity of biological particles on a massive scale, which could be arranged to show the chronological steps of a range of cellular activities.

van der Schot, G. et al: For further details see: Imaging single cells in a beam of live cyanobacteria with an X-ray laser. Nature Communications, 2015; 6: 5704 DOI: 10.1038/ncomms6704

Posted by Tim Sandle