Effect of CPPs on the total cellular uptake (A,B) and endosomal release of dextran (C,D). HeLa cells were incubated for 2 h with 200 μg/mL DextranTMR (A,B) or DextranNF (C,D) in the absence or presence of 5 μM CPP12 or Tat and analyzed by flow cytometry (A and C). (B,D) Comparison of the MFI values of different cell cultures from A and C, respectively. The MFI values are relative to that in the absence of CPP (none; 100%) and represent the mean ± SD for ≥3 sets of independent experiments. n.s., p ≥ 0.05; ***, p < 0.001.