(A) Northern blot assay to detect the cleavage fragments from the hairpin A in HEK293T cells. Probe is complementary to the 5′ stem region of hairpin A marked as a gray underline in Figure 2D. Small RNAs under 200 nt were enriched after siRNA transfection. As a loading control, tRNA was probed. Protein knockdown was confirmed by western blotting.
(B) Northern blot assay. Total RNAs were prepared from HEK293T cells transfected with either empty vector or the plasmid expressing both hairpins.
(C) Northern blot assay. HEK293T cells were fractionated into nucleus and cytoplasm. The RNAs were extracted from each fraction, dissolved in the same amount of TE, and loaded on the gel. Fractionation efficiency is confirmed by measurement of GAPDH mRNA and pri-miR-21 as the cytoplasmic and nuclear markers, respectively.