Figure 4From: Highly pathogenic avian influenza A virus H5N1 NS1 protein induces caspase-dependent apoptosis in human alveolar basal epithelial cellsEnzyme activities of caspase-3 and caspase-9 in NS1-transfected A549 cells. Enzyme activities were detected by Caspase-3/CPP32 Colorimetric Protease Assay and Caspase-9/Mch6 Colorimetric Assay, respectively.Back to article page