Figure 2. Immunostaining of albino mouse outer retina. Sections were labeled with fluorescent probes and analyzed by laser scanning confocal microscopy. The region of outer retina in these images is shown in Figure 1A: Calreticulin, a marker for the endoplasmic reticulum, is found within the RPE cell body but not its apical processes. B: Actin, stained with Alexa Fluor® 488-phalloidin, is found near the basal side of RPE, within RPE and Müller cell apical processes, and at the external limiting membrane. C: CRALBP is found within the entire RPE cell, including the apical processes. Nuclei appear to be labeled in this image; however, this was not a consistent feature of the images and is likely a Z-projection artifact. Distal tips of Muller cells, including their apical processes, are also labeled (pAb UW55). D: CRBP1 distribution in RPE cells is similar to that of CRALBP (mAb F3). E. EBP50/NHERF1 is found within RPE and Müller cell apical processes and, to a lesser extent, within the RPE cell body. The punctate nature of the signal has been a constant feature of our images (pAb B64). F: Ezrin is confined to RPE apical processes (mAb B62). G: RPE65 is found within the cell bodies of RPE cells (pAb PETLET). Apical processes are not labeled. H: RDH5 distribution is similar to that of RPE65 (mAb D9). I: LRAT distribution is similar to those of RPE65 and RDH5 (mAb B1). Images shown are Z-projections created from LSCM image stacks (Z_t=3 μm).