Specific labeling: An effective tool to explore the RNA world

Our knowledge about the functional diversity and importance of RNA in biology has grown enormously over the past three decades and has driven efforts to develop better tools to characterize RNAs. Amongst these tools are methods for preparing specifically labeled or chemically modified RNAs, which are essential for basic research, biomedical, and clinical applications. Understanding the potential and limits of these different RNA synthesis and labeling strategies is important in deciding how to approach the preparation of a particular RNA molecule. Here, we review these various labeling methods and future directions of the field.