Orthogonal Base Pairs Continue to Evolve Review Article

Recent developments in the design and construction of unusual analogs of the natural nucleic acid bases have reached a milestone with the report (in this issue of Chemistry & Biology ) of a new orthogonal base pair that allows site-specific introduction of a photo-crosslinkable modified base into an RNA molecule by T7 RNA polymerase-mediated transcription of DNA containing the base-pairing partner.