Cross Section of <I>Shigella flexneri</I> (IMAGE) Max-Planck-Gesellschaft Caption You can clearly see the two membranes (orange) enclosing the cell interior (blue) and the needles protruding to the outside (orange, marked in blue). The bar corresponds to a micrometer or a thousandth millimeter, respectively. Credit Ulrike Abu Abed, Diane Schad, and Michael Kolbe Usage Restrictions This image may only be used or reproduced for editorial purposes and in connection with scientific articles on our press material, in which case such usage or reproduction is free of charge and requires no permission. Any other use, in particular for commercial purposes, requires prior permission of the author or photographer. Further enquires can be answered in the Press and Public Relations Office - simply write an e-mail to gebhard@gv.mpg.de. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.