Fluorogenic probes for live-cell imaging of the cytoskeleton

Far-red fluorogenic probes for live-cell imaging of either actin or tubulin are described and used for super-resolution microscopy of various structures in a variety of cell types. We introduce far-red, fluorogenic probes that combine minimal cytotoxicity with excellent brightness and photostability for fluorescence imaging of actin and tubulin in living cells. Applied in stimulated emission depletion (STED) microscopy, they reveal the ninefold symmetry of the centrosome and the spatial organization of actin in the axon of cultured rat neurons with a resolution unprecedented for imaging cytoskeletal structures in living cells.