Fig. 2. (A) Ideal structure and thermal kinetic parameters of H1, H2 and the HCR. (B) PAGE analysis of the HCR. Lanes 1–7 represent H1 (2 μM), H2 (2 μM), H1 + H2 (2 μM and 2 μM), H1 + H2 + pre-miRNA-155 (2 μM, 2 μM and 2 μM), H1 + H2 + 2 × pre-miRNA-155 (2 μM, 2 μM and 4 μM), H1 + H2 + 3 × pre-miRNA-155 (2 μM, 2 μM and 6 μM) and the DNA ladder marker, respectively. AFM phase images of the HCR (C) without and (D) with pre-miRNA-155. Scale bar: 500 nm. (E) Cross-sectional profile of the black line in (D).