Figure 17.

Fluorophores may exist in many states but all single fluorophore states fall under two aggregated states: bright and dark. Here there are three states—inactive (I), photobleached (B), and dark (D)—making up the dark aggregate and only one state, active (A), making up the bright aggregate. For this example, with a single dark state there are four rates that fully characterize the photophysics, {k_a, k_d, k_r, k_b}. Reproduced with permission from Geoffrey C. Rollins, Jae Yen Shin, Carlos Bustamante, and Steve Pressé. “Stochastic approach to the molecular counting problem in superresolution microscopy.” Proceedings of the National Academy of Sciences 112, no. 2 (Dec 22, 2014): E110-E118.