Inclusion, GFP expression and glycogen synthesis of pGFP::SW2 transformants of C . trachomatis L2. Untransformed plasmid-replete strain 434/bu (A), untranformed plasmid-free strain L2R (B-D), and transformed L2R selected with either ampicillin (E, G) or chloramphenicol (F, H) were cultured either with medium containing an indicated antibiotic or with antibiotic-free medium. Images of inclusions in unstained and iodine-stained cultures were acquired with phase contrast microscopy or fluorescence microscopy 48 h post-inoculation. In all panels, phase contrast and GFP images are superimposable.