Figure 3.

Schematic representation of the structure of several derivatives of thrombin-binding aptamers (TBAs) prepared in this study. TBA sequence is shown in black, and T4 loop with different sizes of the complementary sequences are shown in red. (a) Native TBA; (b) TBA-hairpin containing three overhanging complementary nucleotides (3-HP-TBA); (c) TBA-hairpin containing six overhanging complementary nucleotides (6-HP-TBA); (d) TBA-hairpin containing nine overhanging complementary nucleotides (9-HP-TBA). Between 3–6 complementary nucleotides are required to disrupt the intramolecular quadruplex to form an intramolecular duplex.