[18a-222-1~11] 12.6 Nanobiotechnology

[18a-222-1] Identification of four-nucleotide single-stranded DNA homopolymers with a solid-state nanopore in alkaline CsCl solution

〇Yusuke Goto¹, Yanagi Itaru¹, Matsui Kazuma¹, Yokoi Takahide¹, Takeda Ken-ichi¹ (1.Hitachi, Ltd., R&D Group)

Keywords:nanopore, DNA sequencer

DNA sequencing via solid-state nanopore is a promising technology with the potential to surpass the performance of conventional sequencers. However, the identification of all four nucleotides with a typical SiN nanopore has yet to be clearly demonstrated because a guanine homopolymer rapidly forms a G-quadruplex in a typical KCl aqueous solution. To address this issue, we introduced an alkaline CsCl aqueous solution, which denatures the G-quadruplex to a single-stranded structure by disrupting the hydrogen-bonding network between the guanines. Using this alkaline CsCl solution, we provided a proof of principle that single-stranded DNA homopolymers of all four nucleotides could be statistically identified according to their blockade currents with the same single nanopore. We also confirmed that a triblock DNA copolymer of three nucleotides exhibited a trimodal Gaussian distribution whose peaks correspond to those of the DNA homopolymers. Our findings will open the door to achieving solid-state nanopore sequencing.