A general method to fine-tune fluorophores for live-cell and in vivo imaging

The paper developed a general method to finely tune the spectral and chemical properties of rhodamine dyes by incorporating 3-substituted azetidine groups. Adding electron-withdrawing substituents on the azetidine ring causes hypsochromic shifts in the absorption and emission maxima, allowing tuning across the visible spectrum. The substituents also modulate the equilibrium between the non-fluorescent lactone and fluorescent zwitterionic forms, enabling rational design of fluorogenic dyes. Using this method they synthesized a series of tuned rhodamines called Janelia Fluor dyes spanning blue to far-red wavelengths. The Janelia Fluor dyes were converted to fluorescent labels for live cell and tissue imaging, demonstrating their brightness, photostability and cell permeability. In particular, Janelia Fluor 585 and 635 showed high fluorogenicity and were used for no-wash labeling in cells and in vivo in mouse brain. Overall, this general tuning method allows rational design of rhodamine dyes with optimized properties for advanced fluorescence microscopy applications. <a href="https://medium.com/@axialxyz/a-general-method-to-fine-tune-fluorophores-for-live-cell-and-in-vivo-imaging-4fbadfce013c">Visit Now</a>