μl of water. The reaction was incubated at 37°C for 60 min. Phosphorylated RNA was purified with the RNeasy MinElute kit (Qiagen) as described above. Purified RNA was concentrated to 6 μl by vacuum centrifugation on a SpeedVac (Eppendorf). One μl of 2 μM pre-adenylated 3’ DNA adaptor, 5’-App/ATC TCG TAT GCC GTC TTC TGC TTG-3' was added to the concentrated RNA. After incubation at 70°C for 2 min followed by chilling on ice for 2 min, the following reagents were added to ligate the adapter at the 3’ end of the RNA; 1 μl of 10× T4 RNA ligase 2 truncated buffer, 0.8 μl of 100 mM MgCl2, 20 U of RNaseOUT and 200 U of RNA ligase 2 truncated (New England Biolabs). After the incubation at 20°C for 60 min, 1 μl of heat-denatured 5 μM 5’ RNA adapter, 5’-guu cag agu ucu aca guc cga cga ucg aaa-3’ was ligated with 3’ adapter ligation products with 20 U of T4 RNA ligase 1 (New England Biolabs) and 1 μl of 10 mM ATP (New England Biolabs) at 20°C for 60 min. 4 μl of adapter ligated RNA was mixed with 1 μl of 20 μM RT Primer,
