Table 2.

An overview of RNA ligation schemes using RNA ligase 1 (RNL1) or RNA ligase 2 (RNL2)

Ligation type	Ligation structure	Ligation conditions
Single-stranded RNAs ligation with RNL1		Molecule I: RNA Molecule II: RNA or DNA
Splint ligation with RNL1		Molecule I: RNA or DNA Molecule II: RNA Molecule III: DNA Resulting hairpin length <8 nt
Y-ligation with RNL1		Molecule I: RNA Molecule II: RNA or DNA Resulting hairpin length <15 nt
Nick ligation with RNL2		Molecule I: RNA Molecule II: RNA or DNA Molecule III: RNA or DNA

The directionality of the ligated nucleic acid strands are denoted by the non-ligated end of each strand. ‘Ligation type’ column includes a common name for a particular ligation reaction and RNA ligase type to be used for a particular ligation. RNA Ligase 1, and RNA Ligase 2 are abbreviated with RNL1 and RNL2, respectively. The ‘Ligation structure’ column provides a schematic representation of the RNA structure to be ligated. The ‘Ligation conditions’ column lists the combinations of nucleic acids resulting in an efficient ligation (107,109).