Interactive flow charts provide information on optical probes, reporter proteins and substrates for in vivo optical imaging.  Bioluminescent enzymes (luciferases), red fluorescent proteins, luciferin, coelenterazine, cleavable luciferins, fluorescent substrates, fluorescent cell stains, labeling probes, vascular probes, targeted probes and enzymatically activatable probes for in vivo optical imaging are covered. The charts are organized by fluorescence imaging versus bioluminescence imaging. Yellow clickable pop ups provide technical information. Click on Spheres for access: