Generation of transgenic NIH 3T3 fibroblast cell lines for selective optogenetic stimulation. (A) Scheme of the plasmid for expression of ChR2 in fusion to mCherry under the control of the CAG promoter. (B) ChR2-mCherry signals (red) in a transfected fibroblast (α-smooth-muscle-actin: white, scale bar 10 µm). (C) FACS profile with percentage of ChR2-mCherry positive cells. (D) Scheme of the plasmid for expression of ArchT in fusion to eYFP under the control of the CAG promoter. (E) ArchT eYFP signals (green) in a transfected fibroblast (α-smooth-muscle-actin: white; scale bar: 10 µm). (F) FACS profile with percentage of ArchT-eYFP positive cells. FACS, fluorescence assisted cell sorting.