Park, JeehaeWerley, Christopher A.Venkatachalam, VeenaKralj, JoelDib-Hajj, Sulayman D.Waxman, Stephen G.Cohen, Adam2014-03-112013Park, Jeehae, Christopher A. Werley, Veena Venkatachalam, Joel M. Kralj, Sulayman D. Dib-Hajj, Stephen G. Waxman, and Adam E. Cohen. 2013. “Screening Fluorescent Voltage Indicators with Spontaneously Spiking HEK Cells.” PLoS ONE 8 (12): e85221. doi:10.1371/journal.pone.0085221. http://dx.doi.org/10.1371/journal.pone.0085221.1932-6203http://nrs.harvard.edu/urn-3:HUL.InstRepos:11879470Development of improved fluorescent voltage indicators is a key challenge in neuroscience, but progress has been hampered by the low throughput of patch-clamp characterization. We introduce a line of non-fluorescent HEK cells that stably express NaV 1.3 and KIR 2.1 and generate spontaneous electrical action potentials. These cells enable rapid, electrode-free screening of speed and sensitivity of voltage sensitive dyes or fluorescent proteins on a standard fluorescence microscope. We screened a small library of mutants of archaerhodopsin 3 (Arch) in spiking HEK cells and identified two mutants with greater voltage-sensitivity than found in previously published Arch voltage indicators.en-USJournal Article2014-03-1110.1371/journal.pone.0085221