Figure 6. Intravitreal injection of labeled siRNA penetrates the retina. A: Confocal microscopy revealed that the scrambled siRNA covalently bound to Cy3 (Red) was distributed throughout the layers of the retina when injected into the eyes of control rats. The label was distributed throughout the retina from the ganglion cell layer (GCL) to the photoreceptor layer (PRL). Nuclei were stained with To-Pro Blue. B: A photomicrograph illustrates panel A with To-Pro Blue removed. Note the distribution of Cy3 labeled siRNA throughout the layers of the retina. C: In contrast, the retinas of rats injected with unlabeled scrambled siRNA did not contain labeled particles, indicating that the label was not due to autofluorescence or artifacts from the injection. Bar=30 um. D: Illustrates higher magnification of inset depicted with dotted rectangle in A. Bar=15 um. IPL=inner plexiform layer, INL=inner nuclear layer. n=3/group.