Development of a Single Molecular Tunnel-Current Identification method For Electrical Genome Sequencing
- PDF / 655,198 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 63 Downloads / 181 Views
Development of a Single Molecular Tunnel-Current Identification method For Electrical Genome Sequencing Takahito Ohshiro, Makusu Tsutsui, Kazumichi Yokota, Tomoji Kawai, Masateru Taniguchi １ 1 Institute of Science and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, Japan
ABSTRACT We developed a tunnel-current based identification method by using nano-gap integrated devices. We performed electrical measurements for mono-nucleotide and oligonucleotide during its translocation of molecules between the nano-gap. Based on this determined electrical conductivity for single-nucleotides, we electrically identify the base-type in oligonucleotides, and found that this time-profiles represents the molecular translocation behaviors inside nano-gap. This method could be a promising for an electrical nucleotide sequencing methodology with label-free, high-speed, and low-cost. INTRODUCTION Low-cost and high-throughput sequencer has been indispensable for a personalized medication. Single-molecule electrical sequencing by nanopore and/or nanogap-integrated devices one of the candidates because of its low-cost and high-speed without PCR amplification ([1]-[3]). In addition, some of them can obtain epigenetic genome information such as methylated cytosine positions in the sequence. Until now, several methodologies has been reported. We have proposed a single-molecule tunnel-current based sequencing (Fig.1a: schematics).
Figure 1: Single-Molecule Tunnel-Current Based Electrical Detection by using nano-gap electrodes. This is based on sequential reading of the tunneling-current across individual single-nucleotides in the sequence by nanogap electrode. The
In this study, we focused on identifications of small DNA/RNA nucleotides, which is important biological target for an analysis of a single-cell transcriptome. Over two hundreds of small nucleotide species expressed in the cell have been discovered and it is found that its small nucleotide family have resemble sequence each other, each of the concentration is quite a low. The sequencing method can be potentially used for both of identification and quantification RNA
analysis. In this method, tunneling-current time-traces is monitored during its translocation of nucleotide molecules through a nano-gap-electrode. Based on difference in the electrical conductivity, we can determined the base-type are sequentially identified. The determined basetype sequence represent the partial sequence. From the assembly of the conductance signal profiles, the resequencing of the original sample sequence was successfully achieved ([4], [5]). EXPERIMENTAL DERAILS We used mechanically controllable break junction (MCBJ) technique for a fabrication of a sensing gap-electrode. The MCBJ was prepared in the following procedure ([6], [7]). First, a gold-wire was fabricated by a standard electron-beam lithography method. The gold-wire was mechanically broken by using a piezo-controller, resulting in forming a pair of gold nanoelectrodes. When the gold-nanowire was gradually bro
Data Loading...
