Fig. 6. Mutant Cx43-eYFP do not form functional gap junctions, as assessed by scrape-loading analysis using sulforhodamine B. Clonal C6 cell lines expressing Cx43-eYFP constructs were analyzed for gap junctional transfer by scrape-loading of sulforhodamine B. (A,B) A representative experiment showing sulforhodamine B or rhodamine-dextran dye-transfer for control C6R(eCFP). No transfer occurs beyond initially loaded cells. (C,D) In wild-type Cx43-eYFP C6R, transfer of sulforhodamine B occurs four to six cell layers beyond initially loaded cells. (E-L) A representative experiment on the mutant Cx43-eYFP shows that all mutants behaved similarly to C6R with absence of dye transfer. Scale bar, 100 µm.