Fig. 4. Western blot for caspase-3, 4, 8, and 9 in celecoxib-treated A549. A549 was treated with celecoxib (0, 25, 50, 75, and 100 µM) for 16 hours. After washing with phosphate buffered saline, cell lysates were obtained using lysis buffer. Western blot for caspase-3, -4, -8, and -9 were performed using antibodies against each caspase, and visualized as described in Materials and Methods. A representative example of six independent experiments is shown. NC, negative control.