Utility of liposomal and free clodronate for microglial elimination. (A) PI staining of MG-5 cells one day after exposure to each clodronate. PI-positive cells (red) indicate dead MG-5 cells. Scale bar, 500 μm. (B) Effects of liposomal and free clodronate on the viability of MG-5 cells. Both forms of clodronate increased the number of dead cells in a concentration-dependent manner after 24 h of exposure. (C) Double immunostaining of MG-5 cells three days after exposure to each clodronate using CD68 (green) and Iba1 (red) antibodies. Scale bar, 200 μm. (D) Effects of liposomal and free clodronate on the viability of MG-5 cells. The number of viable MG-5 cells significantly decreased after exposure to both forms of clodronate. (E) Repeated immunostaining using CD11b and PI antibodies showing the time course of death of MG-5 cells after exposure to both forms of clodronate. Scale bar, 200 μm. Data are presented as the mean ± SEM.