Video 1 - Ingestion of POSs by a cultured primary mouse RPE. The cell was transfected with pEGFP and incubated with Texas red-X-labeled mouse POSs. It was analyzed by time-lapse microscopy, using a spinning disk confocal microscope system (UltraVIEW ERS). A stack of images was obtained of 102 different z-axis planes, 0.2 µm apart, every 62 s. Volocity software was used to reconstruct the 3D images. The movie comprises 3D images from seven z-stacks, and its playback rate is one 3D image per second (i.e., 62 times real speed). Images of individual frames of this video are shown in Fig. 1 A.