Figure 3.

Overview of modification options explored in this study. a) Incorporation of NPE and DEACM photocaging groups for wavelength‐selective uncaging experiments. An overlay of HPLC traces before and after sequential uncaging is shown. b) 3′‐Extension and splinted ligation of DNA/RNA chimera with either a phosphodiester or a phoshorothioate (*) backbone. c) 3′‐Extension of 2′‐OMe RNA was unfortunately not possible. d) NaIO₄‐capping of the 3′‐end of unmodified RNA allows a following rhodamine modification using morpholino chemistry. e) Introduction of a photocleavable linker enables light‐induced cleavage of the 5′‐biotin tag after the incorporation of mAzo photoswitches into RNA. f) Enzymatic incorporation of an internal photocleavable strand break unit that could be used for light‐induced backbone cleavage at defined positions.