Figure 7. Texas red microsphere were delivered to retinal pigment epithelium/retina interface. The contralateral optic vesicle was injected with the microspheres at stage 26. A: At stage 28, the embryo was embedded in methacrylate polymer. At this stage, formation of the optic cup is complete and melanin pigment is visible in the retinal pigment epithelium. B: The same section photographed under fluorescence shows the microspheres appearing as red dots (arrows) along the RPE/retina interface.