Chelidonine-induced apoptosis is partially inhibited by anti-apoptotic Bcl-2/b>: Jurkat Vector and Bcl-2 overexpressing cells were treated for 24 h with medium supplemented with solvent or 1, 5, 10, 50 and 100 μM chelidonine. Apoptosis induction was then quantified using (a) light scatter characteristics to determine cellular shrinkage, (b) TMRE-staining to detect alterations of mitochondrial membrane potential Δψm, and (c) CaspACE®-staining to test caspase-activation. Data show means ± SD (n = 3). Paired t-test was performed using GraphPad InStat version 3.00 for Windows 95, GraphPad Software, San Diego California USA, http://www.graphpad.com. (d) Combined staining with Hoechst33342 and propidium iodide of Jurkat Vector cells treated for 24 h with medium or 100 μM chelidonine revealed massive apoptosis while apoptosis rates were reduced in Bcl-2 overexpressing Jurkat cells.