Development of a riboswitch-based platform for live cell imaging of RNAs in mammalian cells

RNAs directly regulate a vast array of cellular processes, emphasizing the need for robust approaches to fluorescently tag and track RNAs in living cells. Here, we develop an RNA imaging platform using the Cobalamin (Cbl) riboswitch as an RNA aptamer and a series of probes containing Cbl as a fluorescent quencher linked to a range of fluorophores. We demonstrate fluorescence turn-on upon RNA binding and proof of concept for tracking both mRNA and small U RNA in live cells.