C9i induces changes in cell permeability and loss of ΔΨm in a dose-dependent manner. BLIN-3 cells were cultured in the absence of adherent fibroblasts for 8 hours under the conditions shown and analyzed for changes in cell permeability (YO-PRO) or ΔΨm (TMRE). Designations at the top of each contour plot or histogram indicate caspase inhibitor concentration in μM. FIBRO^- refers to BLIN-3 cells removed from fibroblasts and tested immediately. DMSO indicates vehicle control; and STSP, positive control for induction of apoptosis. Numbers in contour plots indicate percentage of YO-PRO⁺/PI^- cells. Numbers in histograms indicate percentage of PI^- cells that underwent a loss of ΔΨm. Similar results were obtained in 2 other experiments.