Rapid and reliable RNA resonance assignment by combining chemical and enzymatic stable isotope labeling

•Fast and reliable resonance assignment of aromatic CH and imino NH resonances of RNAs comprising up to 65 nucleotides.•RNA resonance assignment is possible even if spectral quality is low.•NMR measurement times for RNA resonance assignment can be cut by a factor of 4.•An expedient expansion to existing RNA NMR protocols and competitive in terms of workload, NMR measurement times and costs.