Identification of coumarin derivatives visualizing the multiple layers of the zebrafish retina in vivo. Zebrafish larvae at 6 dpf were stained with BODEC (A), MBODEC (B), BTDEC (C), BIDEC (D), BIC (E), BIDPC (F), DIBPBC (G) and DOBPBC (H). The retinas were visualized by confocal laser scanning microscopy. The zebrafish retinas are clearly visualized by BODEC (A), MBODEC (B), BTDEC (C) and DIBPBC (G). OPL: outer plexiform layer; ONL: outer nuclear layer; PCL: photoreceptor layer; GCL: ganglion cell layer; IPL: inner plexiform layer; INL: inner nuclear layer.