Phys. Rev. Lett. 112, 088102 (2014)

Credit: © 2014 APS

Diffraction techniques based on X-rays are routinely used to determine the structure and composition of materials ranging from inorganic minerals to biological specimens. Recent technical developments have made very small beam sizes possible, which, in turn, allows for small samples to be probed, well below the size of biological cells. However, analysing the structure of actual living cells remains a challenge due to their weak contrast. One way of enhancing this is to investigate the cells in dried form, but this comes at the cost of observing them in their natural state. To overcome this limitation, Britta Weinhausen and colleagues have developed a microfluidic device that mimics their natural environment, and is transparent to X-rays. By passing the cells through an X-ray beam that is only a few hundred nanometres wide, they are able to image them while they are alive, and show that chemically fixed cells tend to display artefacts. Scientists looking to perform X-ray imaging studies of biological material in the future should take note.