Fig. 1.

PP6 cell morphology at various culture time points. a Round, fusiform, or spindle-shaped adherent cells (green arrows), and a small number of cells in suspension (yellow arrow). b After 72 h of culture, the number of cells in suspension decreased and the number of adherent cells increased, most of which were fusiform or spindle-shaped. c At days 5–7 of culture, cell proliferation occurred and the size of the cells increased. d At days 12–14, the cell density increased. e At days 14–16, high confluence percentage was observed. (Color figure online)