Three-Dimensional Control of DNA Hybridization by Orthogonal Two-Color Two-Photon Uncaging

We successfully introduced two‐photon‐sensitive photolabile groups ([7‐(diethylamino)coumarin‐4‐yl]methyl and p‐dialkylaminonitrobiphenyl) into DNA strands and demonstrated their suitability for three‐dimensional photorelease. To visualize the uncaging, we used a fluorescence readout based on double‐strand displacement in a hydrogel and in neurons. Orthogonal two‐photon uncaging of the two cages is possible, thus enabling complex scenarios of three‐dimensional control of hybridization with light. Now also in 3D! Oligonucleotides with different sequences could be photoactivated with exact three‐dimensional control when different two‐photon‐sensitive photolabile groups were introduced into the strands. Uncaging was visualized by fluorescence as a result of double‐strand displacement. By using distinct irradiation conditions, either one of two sequences could be addressed selectively (see left‐hand images, which are overlayed on the right).