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 Heejun Choi A1 Anand K. Muthusamy A1 Brian P. Mehl A1 Peng Dong A1 Timothy A. Brown A1 Jennifer Lippincott-Schwartz A1 Zhe Liu A1 Timothée Lionnet A1 Luke D. Lavis YR 2016 UL http://biorxiv.org/content/early/2016/07/29/066779.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 novel 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 live-cell labeling strategies. These compounds retain the superior brightness of the JF dyes once activated, but their facile photoactivation also enables improved single-particle tracking and localization microscopy experiments.