Q-dot labeling and detection by SEM. HeLa cells were infected with <i>Chlamydia trachomatis</i> elementary bodies, probed with anti-chlamydial rabbit serum, and labeled with anti-rabbit Q-dots (565nm peak emission). Panels A–C demonstrates examination of clustered elementary bodies on the surface of infected HeLa cells by fluorescence/light microscopy, TEM, and SEM, respectively. Scale bars = 500 nm unless designated).