Reverse transcription as key step in RNA evolution with unnatural base pairs.

Unnatural base pairs (UBPs) augment the chemical diversity of artificial nucleic acids and can thus enable the generation of new aptamers and catalytic nucleic acids by selection. However, owing to a lack of methodologies, the reverse transcription of UBPs, a key step in RNA aptamer selection, has not been sufficiently characterized. Here, we present a series of versatile assays to investigate the reverse transcription of the TPT3:NaM base pair as a representative for hydrophobic unnatural base pairs.