Fig. 1.

mEos2 blinks in its photoactivated red form. (A) Single-molecule fluorescence detected with an EMCCD camera shows spatially distinct individual molecules. (Scale bar, 1 μm.) (B) Time trace of emission intensity (orange line) and (C) EMCCD images of a single mEos2 (red box from A) show two transitions to dark states, followed by photobleach. (D) Localized positions (+ symbol) of each of the three images from C are spatially indistinguishable within the localization uncertainty (white circle, 1σ). (Scale bar, 10 nm.)