Fig. 4. The effect of BFA on Cx32-CFP and Cx26-YFP in co-transfected COS-7 cells. COS-7 cells were co-transfected with cDNA encoding Cx32-CFP and Cx26-YFP. Cells expressing both proteins were examined before and after BFA treatment. (A-C) No drug treatment. Cx32-CFP (A), Cx26-YFP (B) and merged image (C) showing colocalisation of both proteins especially at a presumed gap junction. (D-F) Cells treated with BFA for 6 hours. Cx32-CFP (D), Cx26-YFP (E) and merged image (F) showing absence of Cx32-CFP at the plasma membrane. For the purpose of image analysis CFP was assigned to the red channel and YFP to the green channel, resulting colocalisation in the merged image is yellow. Bar, 10 µm. Arrows indicate targeting to gap junctions.