Fig. 9. Photostability of AlexaFluor Phalloidin 532 (top) and Ru-ER (bottom) after 1, 15, and 30 frames of STED images acquired (a), and the corresponding emission intensity plot over the 30 frames (b). AlexaFluor Phalloidin 532 was excited at 528 nm white light laser, and the emission collected between 534 and 675 nm. Ru-ER was excited at 488 nm and emission collected between 590 and 700 nm. The 660 nm STED laser was used to acquire STED images of both samples at 0.05 W. Bottom, Ln (emission intensity) versus time plots for photobleaching of each probe under identical STED imaging conditions.