FIG 2.

Visualization of E. coli ghosts using confocal fluorescence microscopy and electron microscopy. (A) E. coli EC452 cells and ghosts derived from EC452 were visualized using fluorescence microscopy. The left panel shows EC452 cells that produce GFP in the cytoplasm and harbor pRL1. The cells were incubated with the red fluorescent membrane dye FM4-64 and subsequently visualized using fluorescence microscopy by simultaneously monitoring the fluorescent signals from GFP and FM4-64. The right panel shows a ghost isolated 120 min after the addition of l-rhamnose to the cells shown in the left panel. Bars, 1 μm. (B) The fluorescence microscopy-based analysis of cells and ghosts shown in panel A was verified on a population level using flow cytometry. Both GFP fluorescence and granularity (inset) were monitored. Green line, cells; black line, ghosts; a.u., arbitary units. (C) Cells (left panel) and ghosts (right panel) used for images in panel A were fixed, stained, and visualized by EM. Bars, 2 μm.