Figure 3. Direct observation of d2EGFP fluorescence in retina. Representative fluorescence microscopic images of adult rat retina sampled at 24:00 h. A: Detection of d2EGFP fluorescence in transverse retinal sections. Note the abundance of ONL and IS expression as localized in (B) by the corresponding DAPI-merged image. C: Detection of d2EGFP fluorescence in flat-mounted freshly dissected retinal tissue from transgenic, but not wild-type animals (D). Bars=20 μm. Abbreviations: OS, photoreceptor outer segment; IS, photoreceptor inner segment; ONL, outer nuclear layer; INL, inner nuclear layer; GCL, ganglion cell layer.