This month's winning image was submitted by Olivier Schwartz (Virus and Immunity Group, Institut Pasteur, Paris, France (schwartz@pasteur.fr)). It shows a dendritic cell sensing a lymphocyte.

Blue and pink pseudo-colouring highlight a human dendritic cell and a lymphocyte, respectively. The dendritic cell scans the surface of the lymphocyte, which could lead to the creation of an immunological synapse. The image was obtained using a field emission scanning electron microscope (JEOL 6700F). Bar, 1 μm.

The winner would like to acknowledge the help of Nathalie Sol-Foulon (Virus and Immunity Group, Institut Pasteur), as well as Stéphanie Guadagnini and Marie-Christine Prevost (both at the Electron Microscopy Core Facility, Institut Pasteur).