Detection of duplex RNA binding affinity of 2b and 2blm by electrophoretic mobility shift assay (EMSA). (A) Purified glutathione‐S‐transferase (GST)‐tagged proteins used in EMSAs were separated and stained by Coomassie brilliant blue. M, marker. (B) Comparative EMSAs carried out with increasing amounts (0.025–5.00 μg) of GST‐2b or GST‐2blm and a constant amount (1 nm) of [γ‐32P]‐labelled, 21‐bp, double‐stranded (ds), small interfering RNAs (siRNAs) with 2‐nucleotide 3′ overhangs. (C) EMSAs to compare the binding activities of 2b and 2blm with 55‐bp dsRNAs. Bound and free probes are indicated. GST (G) and GST‐p19 were used as negative and positive controls, respectively.