Fig. 8 Pulse-chase imaging with super-resolution PALM using fusion proteins with mIrisFP.
(a)-(d) Schematic depiction of the experiment. (a) Only a few protein molecules fluoresce in the
green at any given point in time ( bright green dots ); the majority is in the dark state ( dark-green
dots ). By sequential activation and localization, a PALM image can be taken. (b) Molecules in the
area marked by the violet rectangle are photoconverted to the red form by 400-nm light irradiation.
(c) Again, only a small subfraction is in the fluorescent state at any point in time ( bright red dots ),
the majority is in the dark state ( dark-red dots ). (d) Red molecules migrate to other regions of the
cell that were not irradiated with 400-nm light, where they are subsequently localized. (e) PALM
image using green IrisFP .(f) Targeted photoconversion of a mIrisFP subpopulation to the red
state .(g) PALM image using red mIrisFP , showing that red-converted molecules migrate to other
regions of the cell