Measuring reagent and analysis device for analyzing biopolymer
An object of the present invention is to solve inhibition of biopolymer measurement in a nanopore, which involves three-dimensional conformation of a biopolymer containing a nucleic acid. The present invention provides a device for analyzing a biopolymer containing a nucleic acid, the device including: an array device including a plurality of thin film parts having a nanopore; a single common container and a plurality of individual containers capable of storing a measurement solution which is brought into contact with the thin films; and individual electrodes respectively provided in the plurality of individual containers, wherein: the measurement solution is introduced into each of the individual containers and the common container so as to be brought into contact with the thin films; and the measurement solution has a pH equal to or greater than pKa of a guanine base and contains cesium ions as electrolyte cations.
1. A method for analyzing a biopolymer, comprising:
preparing a device comprising: a thin film of a solid state silicon based substrate having a nanopore; a pair of containers capable of storing a measurement solution which is brought into contact with the thin film; and a pair of electrodes provided in each of the containers;
depronating hydrogen present at the N−1 position of the guanine bases, causing the hydrogen bond between the guanine bases to weaken and correspondingly weaken an aggregate forming force among the guanine bases, and using cesium ions as electrolyte cations in the measurement solution for inhibiting the guanine bases from forming a tetramer (G-quadruplex) that blocks the nanopore;
passing a biopolymer comprising a nucleic acid through the nanopore formed in the thin film; and
analyzing the biopolymer based on a change in an electrical signal due to the pass of the biopolymer through the nanopore.
2. The method for analyzing a biopolymer according to claim 1 , wherein the solution comprises halide ions as electrolyte anions.
3. The method for analyzing a biopolymer according to claim 1 , wherein the solution has a pH equal to or greater than pKa of the guanine base and equal to or less than pH 14.
4. The method for analyzing a biopolymer according to claim 1 , wherein the solution has a pH adjusted to be equal to or greater than pKa of the guanine base and equal to or less than pH 14 by adding cesium hydroxide.
5. The method for analyzing a biopolymer according to claim 1 , wherein the solution has a pH adjusted to be equal to or greater than pKa of the guanine base (N−1 position) and equal to or less than pH 14 by a pH adjuster according to the equation of Henderson-Hasselbalch pH=pKa+log 10[HX+]/[X], wherein X refers to the pH adjuster.
6. The method for analyzing a biopolymer according to claim 5 , wherein the pH adjuster has a concentration equal to or greater than 100 mM.
7. The method for analyzing a biopolymer according to claim 1 , wherein the solution has a cesium ion concentration equal to or greater than 10 mM and equal to or less than a saturated concentration.
8. The method for analyzing a biopolymer according to claim 1 , wherein the biopolymer is RNA, DNA or PNA, or a combination thereof.
9. The method for analyzing a biopolymer according to claim 1 , wherein the substrate is one of silicon nitride (SiN), silicon oxide (SiO2) and silicon oxynitride (SiON).