Far-Red Switching Dna Probes For Live Cell Nanoscopy

Herein we present DNA probes composed of Hoechst 33258 and spontaneously blinking far-red hydroxymethyl silicon-rhodamine (HMSiR). The best performing probe, 5-HMSiR-Hoechst, contains the 5'-regioisomer, shows similar to 400-fold fluorescence increase upon DNA binding and is compatible with wash-free single molecule localization and 3D stimulated emission depletion microscopy of chromatin nanostructures in living cells.