Figure 5. Immunofluorescence analysis of GPR109A protein in ARPE-19, rMC-1, and RGC-5 cells. A: ARPE-19 cells incubated with anti-GPR109A antibody, which detects both GPR109A and GPR109B, were highly positive. B: Cells incubated with primary GPR109A antibody neutralized by incubation with excess antigenic peptide did not display any positive signal. Likewise, no positive signal was detected in rat Müller (rMC-1; C) and retinal ganglion-5 (RGC-5; D) cells incubated with anti- GPR109A antibody.