A Two-Photon-Photocleavable Linker for Triggering Light-Induced Strand Breaks in Oligonucleotides.

We synthesized a two-photon-sensitive photocleavable linker based on the 7-diethylaminocoumarin structure and introduced it successfully into DNA strands. First, we demonstrated the inducibility of strand scissions upon irradiation at 365 nm. To verify and visualize the two-photon activity, we used a fluorescence assay based on a DNA strand displacement immobilized in a hydrogel.

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.

Four levels of wavelength-selective uncaging for oligonucleotides.

In this study the new nucleobase-caged nucleotides dT(NpHP) and dT(DEACM) are introduced. Together with two other caging groups (NDBF and NPP) this results in four layers of wavelength-selective uncaging for oligonucleotides, sequentially going from 505 to 440 nm, 365 nm, and finally to 313 nm for the photolysis reaction.