Polarized morphology of parotid acini. (A) A transmitted laser light image is shown of a small group of cells characteristic of those used throughout this study. The positions of secretory granules (SG), nucleus (NU), apical membrane (AM), lateral membrane (LM), and basal membrane (BM) are annotated. The position of apical (red dot), lateral (green dot), and basal (blue dot) photolysis sites is shown. (B) A maximum projection image, constructed from a z-series, is shown from a small group of cells stained with live cell markers of the nucleus (blue), granules (red), and PM (green). (C) A similar triplet was stained to indicate PM (green), nucleus (blue), and mitochondria (red). (D) Similar staining was performed in a parotid lobule not subjected to enzymatic digestion and indicates the similar localization of granules (red), PM (green), and nuclei (blue).