RBPMS immunoreactivity was mainly expressed in medium and large cells in the monkey GCL. Monkey whole-mounted retinas immunostained with RBPMS antibodies and counterstained with DRAQ5 or NeuN antibodies. DRAQ5 labeled all nuclei, and NeuN immunoreactivity was expressed in the nucleus and cytoplasm of RGC and displaced amacrine cell somata. Note that there was a greater number of small DRAQ5 stained nuclei than small diameter NeuN immunoreactive cells at the same retinal eccentricity, suggesting NeuN is expressed by some, but not all displaced amacrine cells. A, D: RBPMS. B: DRAQ5. E: NeuN. C, F: Merged images. Both sets of images are from the same peripheral retinal location. Plane of focus in GCL for all images. z-step = 0.47 μm. 8 optical sections were compressed for viewing. RBPMS antibody GP15029. Scale bar = 20 μm.