ClC-3 is important for PAF-induced apoptosis. A quantitative ELISA for histone-associated cytoplasmic DNA fragments was used to measure apoptosis in IEC-6 cells, ClC-3 shRNA-transfected IEC-6 cells, and control shRNA-transfected IEC-6 cells treated with 3 μM PAF or vehicle control (C). Each experiment was run in quadruplicate (4 wells/experiment, n = 3 separate experiments), and the mean of the 4 control values was used to standardize values within each experiment as percent of control with control being assigned a value of 100%. Asterisk denotes statistical significance at P < 0.05 compared with control. As shown, PAF induces significant apoptosis in both native and control shRNA-transfected IEC-6 cells but does not induce significant apoptosis in ClC-3 knockdown cells.