The growing interest in single-molecule analysis of RNA calls for programmable enzymatic labeling strategies beyond the horizon of solid-phase synthesized RNAs. Herein we describe an easy and versatile chemo-enzymatic approach to label RNA at its termini or defined internal positions via click-chemistry.

Without labeling RNA: A new rapid assay for micro-RNA maturation was developed. The assay depends on the cleavage of unmodified pre-miRNAs and the subsequent amplification of the mature miRNA by rolling circle amplification (see accompanying scheme).