Figure 2. Transfection with the modified capillary gun labels retinal ganglion cells (RGCs) to their distal tips. A, B: Transfection of a retinal explant with YFP permits visualization of numerous RGCs and their axons, which course toward the optic nerve head. C-F: By 48 h after transfection, RGC somata and dendrites are fully labeled with fluorescent protein and show no evidence of blebs or degeneration after transfection with the modified capillary gun. G-I: The micro-targeting capacity of the gun permits clear visualization of YFP-filled RGC axons, which are smooth, straight, and devoid of varicosities in the region near the optic nerve head. Scale bar represents 100 μm in A and B and 50 μm in C-I.