Figure 4. Mitochondria transmembrane potential and caspase activities measurement. HeLa-CD4 cells were transfected with pcWNV-Cp-DJY (a) or pcDNA3.1 (b), and their mitochondria transmembrane potential was measured after 48 h by ultraviolete illumination. A colorimetric caspase activity assay was performed with pcWNV-Cp-DJY– or pcDNA3.1-transfected cells for caspase-3 (c) or caspase-9 (d) activity. As a specificity control, the inhibitor LEHD-FMK for caspase-9 was added to the reactions along with relevant substrate (d). A specific positive control was used for assay validation (magnification: 1000X [a and b]).