Double fluorescent labelling of a bipolar epithelial cell in vitro: The outer hair cell.

Background: Fluorescence membrane markers are efficient tools for visualizing the dynamics of membrane recycling processes in living cells. The outer hair cell (OHC) - a bipolar epithelial cell in the cochlea - possesses endocytic activity at both its apical and basal poles. The best visual overview of transcytosis in the OHC is achieved when the cell is isolated, so that both the apical and the basal poles are in the same focal plane to allow confocal imaging.