Figure 5

Cell penetration efficiency of the CPP library. (a) BY-2 cell penetration efficiency of 55 types of CPPs. The type of CPP is shown as peptide number and is listed in Table 1. BY-2 cell was evaluated after a 3-h incubation at 26 °C. For cell penetration, the peptide concentration and cell density were 100 µg/mL and approximately 380 cells/µL, respectively. All data are expressed as the means ± S.D. from triplicate tests; the mean data labeled with different letters (x, y, and z) are significantly different (Tukey’s HSD test, P < 0.05). (b) CLSM images of the eight CPPs with the highest cell penetration efficiency. The images are overlays of DIC (gray scale) and TAMRA fluorescence (red). Scale bars, 100 µm. (c) Relationship between the cell penetrating efficiency and dead cell rate of 55 types of CPPs. The dead cell rates are converted from Fig. S5.