Representative fluorescence micrographs of internalization of <i>C. difficile</i> spores by Raw 264.7 cells.

<p><i>C. difficile</i> spores were labeled with biotoin and Alexa Fluor 488 (green) prior to infection of monolayers of Raw 264.7 cells (red). Infected Raw 264.7 cells were washed; fixed and extracellular spores were stained with Streptavidin-Alexa Fluor 350 conjugate (blue), stained for F-actin and analyzed by fluorescence microscopy as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043635#s2" target="_blank">Methods</a> section. Representative micrographs of phagocytosis of <i>C. difficile</i> spores are shown: A) Extracellular <i>C. difficile</i> spores (blue); B) Total <i>C. difficile</i> spores (green); C) Merged images. Bars represent 5 µm. White arrows highlight internalized spores.