Figure 1.

Electron micrographs of C. trachomatis serovar E (left panel) and serovar L2 (right panel) samples prepared by using Gastrografin^® gradient centrifugation. Based on their characteristic morphological features, a mixture of EBs and RBs was detected in both preparations. EBs (black arrows) contain highly condensed material appearing as electron-dense and electron-lucent, whereas RBs (white arrows) represent larger structures containing relaxed, reticulated nucleoid material. Intermediate morphologies where characteristics of both are observed may represent IBs (grey arrows).