Figure 1.

A representative sampling of historical and currently favored genetically-encoded fluorescent probes are classified by excitation wavelength and fluorescence quantum yield. The relative size of each fluorophore, taking both polypeptide molecular mass and oligomeric status into account, is proportional to the diameter of its marker. Quantum yields and emission wavelengths are taken from the literature (Johnson et al., 1962; Ormö et al., 1996; Rizzo et al., 2004; Shaner et al., 2004; Shcherbo et al., 2007, 2009; Shu et al., 2009; Auldridge et al., 2012; Christie et al., 2012; Filonov and Verkhusha, 2013; Shcherbakova and Verkhusha, 2013; Yu et al., 2014) except for WiPhy2 (this work).