Figure 2. Increasing numbers of fluorescently labeled porcine POS are phagocytosed by HESC-derived RPE over time. A monolayer of HESC-derived RPE cells was exposed to Alexa Fluor® 488-labeled porcine POS, treated with trypan blue to remove fluorescent non-internalized POS, washed, fixed, and processed for immunocytochemistry. Representative micrographs are shown from (A) 1 h and (B) 20 h together with respective Nomarski images (C and D). Alexa Fluor® 488-labeled POS are in green. Scale bars equal 50 μm. E Increased internalization of POS was observed over time. Data shown are mean±SEM p<0.001, One-way ANOVA with Bonferroni multicomparison test, (n=5); 0.5 h versus 4 h p<0.05, 0.5 h versus 20 h p<0.001, 1 h versus 20 h p<0.001, 4 h versus 20 h p<0.05.