We extend our currently working fast SIM setup by a nonlinear structured illumination option.
Exploiting nonlinear fluorescence propeties, such as photoswitchabilitiy or saturability it is possible to undergo the limited resolution of SIM by an additional factor of 2 (or even more, dependent on the amount of nonlinear grating orders that are used).
At the moment, we use Kohinoor a special derviate of teh Green Fluorescent protein (GFP) as nonlinear dye. Kohinoor is a photoswitchable dye, which can be deactivated by light at 405 nm. From there, it can be brougth back to a photoactive state using 488 nm radion. The photoactive state can be excited by 488 nm as well.