SK-N-MC neuroblastoma cells immunolabeled for active caspase 3 and C. pneumoniae inclusions following induction of apoptosis with staurosporine. Anti-caspase 3 specific for activated caspase 3 (red); DAPI to reveal the nuclear profile (blue); anti-chlamydial antibody specific for chlamydial inclusions (green). Shown are uninfected (A, B) and infected cells for 24 (C, D), 48 (E, F) and 72 (G, H) hours post infection, untreated cells (A, C, E, G) and cells treated with 1 μM staurosporine for 4 hours (B, D, F, H). Mag. bar = 20 μm.