RNA imaging in live cells

Traditional molecular biology tools have elucidated the identities and functions of RNA molecules, which are essential to the understanding of gene transcription and protein translation. Deepening this research field would further require the direct visualization of RNA dynamics such as the DNA-RNA interactions and RNA-protein interactions. Towards this goal, the rise of RNA imaging tools over the past 15 years has reformed how we looked at these processes. In this emerging topic, we first highlighted recent advances on three main RNA imaging tools based on the species of interacting molecules: RNA-RNA pairing, RNA-protein binding, and small molecule-RNA complex. We introduced the advantages of these tools from a technical viewpoint, including binding affinity, fluorescent turn-on ratio, stability, and impacts on targeted RNA. Next, we discussed new rising opportunities and future directions, echoing the state-of-the-art imaging tools in the fields of fluorescent proteins and small fluorescent molecules. Together, we believe this emerging field will bring new insights on how we study RNA biology in living systems.