Figure 2

Analysis of the responsiveness of Opto-RANK cells to blue light using TRAP staining. (a–b) Opto-RANKm cells were cultured on a collagen-coated plate without (a) or with (b) blue light exposure every 2 min, for 5 d, and then stained for TRAP. (b′) A higher magnification view of the staining in (b). (c–d) Opto-RANKc cells were cultured on a collagen-coated plate without (c) or with (d) blue light exposure every 2 min for 5 d and then stained for TRAP. (d′) Higher magnification views of the staining in (d). Arrows and arrow heads indicate multinucleated and mononuclear cells, respectively. Scale bar: 150 μm. RANK, receptor activator of nuclear factor-kB; TRAP, tartrate-resistant acid phosphatase.