1c1c7 cultures were left untreated or treated with 33 μM NPe6, light or NPe6+light in the absence or presence of various concentrations of 3-O-MeSM. Some cultures were incubated with NPe6 and/or 3-O-MeSM for 1 h and 30 min respectively before being washed, re-fed and irradiated. Approximately 30 min after irradiation, cultures were loaded with AO and HO33342 and imaged 10 min later. (A) Untreated cultures, (B) cultures treated with NPe6, (C) 80 s of light, (D) 50 μM 3-O-MeSM, (E–H) NPe6+40 s of light±various concentrations of 3-O-MeSM and (I–L) NPe6+80 s of light±various concentrations of 3-O-MeSM. (A) Scale bar, 10 μm.