Fig. 3. Subcellular localization of Cx43-eYFP fusion proteins reveals formation of punctate structures at cell-cell junctions. Immunofluorescence microscopy of live cells growing on glass coverslips was performed on a custom laser-scanning confocal microscope equipped with a blue diode laser (475 nm) using a 63x1.3 objective. These data are representative of separate experiments on two cell lines for each construct. (A) Uninfected C6R was included as a control demonstrating lack of fluorescence signal. Mutants L90V (G) and I130T (H) showed a slightly reduced abundance of puncta, while mutants Y17S (C), G21R (D) and A40V (E) formed significantly fewer puncta than wild type. F52dup appeared to be localized at the cell membrane with only occasional formation of punctate structures at the cell surface (F). Scale bar, 10 µm.