Infectivity assay of Chlamydiae infected monocytes and monocyte-derived DCs. Monocytes (upper panel) and human monocyte-derived DCs (lower panel) were infected with C. trachomatis serovars Ba, D and L2 (MOI-3) for 2 days and were further passaged in HeLa cells for 2 days. Chlamydial inclusions (green) were stained with FITC conjugated anti-chlamydia LPS antibody and counterstained with Evans Blue. Pictures taken at 40X magnification with Leica DMLB. The figures are representative of 3 independent experiments.