Fig. 5. Caspase-3 activity localization studies in cellular compartments. Cultures of A2780 cells were grown in 8-well chambers. The cells were treated with cisplatin for 48 h then 22 was added to growth media for additional 24 h. Lysotracker, Mitotracker or ER-tracker was added and cells were imaged with an inverted fluorescent microscope. (a) Green fluorescence cell tracker; (b) red fluorescence, caspase-3 activity from 22; (c) yellow color, overlap of red and green signal. Active caspase-3 was detected in mitochondria and ER compartments. Scale bar 10 μm. (d) A2780 cells were induced to undergo apoptosis with cisplatin for 30 hours then 22 was added and pictures were acquired every 15 minutes over the next 48 hours to generate a time lapse movie (ESI Movie 1†). Pictures extracted from the time laps movie are presented. The indicated time corresponds to the start of cisplatin treatment. Red indicates Cy5 fluorescence from 22 seen overlaid bright field images.