Double stain immunofluorescence for unphosphorylated connexin 43 and alpha smooth muscle actin. (a) Double stain immunofluorescence using FITC labelled unphosphorylated connexin 43 (green) and TRITc labelled alpha SMA (red). Again, cells expressing unphosphorylated connexin 43 are identified on the boundaries of smooth muscle bundles. The Myometrial biopsy is from a woman in spontaneous labour at term (Bar = 50 micrometres). (b) A higher-powered view of the same biopsy from a woman in spontaneous labour at term showing dendritic processes reaching between the myocytes. The antibody is bound evenly to the entire surface of the cell (Bar = 10 micrometres).