RT Journal Article SR Electronic T1 Bright photoactivatable fluorophores for single-molecule imaging JF bioRxiv FD Cold Spring Harbor Laboratory SP 066779 DO 10.1101/066779 A1 Jonathan B. Grimm A1 Brian P. English A1 Anand K. Muthusamy A1 Brian P. Mehl A1 Peng Dong A1 Timothy A. Brown A1 Zhe Liu A1 Timothée Lionnet A1 Luke D. Lavis YR 2016 UL http://biorxiv.org/content/early/2016/08/04/066779.abstract AB Small molecule fluorophores are important tools for advanced imaging experiments. The development of self-labeling protein tags such as the HaloTag and SNAP-tag has expanded the utility of chemical dyes in live-cell microscopy. We recently described a general method for improving the brightness and photostability of small, cell-permeable fluorophores, resulting in the azetidine-containing “Janelia Fluor” (JF) dyes. Here, we refine and extend the utility of the JF dyes by synthesizing photoactivatable derivatives that are compatible with established live-cell labeling strategies. These compounds retain the superior brightness of the JF dyes but their facile photoactivation enables improved single-particle tracking and localization microscopy experiments.