HYBRIDIZATION ASSISTED NANOPORE SEQUENCING
A method of employing a nanopore structure in a manner that allows the detection of the positions (relative and/or absolute) of nucleic acid probes that are hybridized onto a single-stranded nucleic acid molecule. In accordance with the method the strand of interest is hybridized with a probe having a known sequence. The strand and hybridized probes are translocated through a nanopore. The fluctuations in current measured across the nanopore will vary as a function of time corresponding to the passing of a probe attachment point along the strand. These fluctuations in current are then used to determine the attachment positions of the probes along the strand of interest. This probe position data is then fed into a computer algorithm that returns the sequence of the strand of interest.
1 . A method for determining the sequence of a biomolecule strand of interest, comprising the steps of:
providing a sequencing apparatus having a first fluid chamber, a second fluid chamber, a membrane positioned between said first and second chambers and a nanopore extending through said membrane such that said first and second chambers are in fluid communication via said nanopore;
providing a single-stranded biomolecule;
providing a first plurality of matching probes having a known sequence;
hybridizing said first plurality of probes with said single-stranded biomolecule such that said first plurality of probes attach to portions of said single-stranded biomolecule to produce a partially hybridized biomolecule;
introducing said partially hybridized biomolecule into said first chamber;
translocating said partially hybridized biomolecule from said first chamber through said nanopore and into said second chamber;
monitoring changes in current across said nanopore as said partially hybridized biomolecule is translocated therethrough, said changes in electrical potential corresponding to locations along said partially hybridized biomolecule containing one of said first plurality of probes; and
recording said changes in electrical potential as a function of time.
2 . The method of claim 1 , wherein said method is repeated using a second plurality of matching probes having a known sequence different than said known sequence of said first plurality of probes.
3 . The method of claim 1 , wherein said probes are hybridizing oligonucleotides having n number of bases therein.
4 . The method of claim 3 , wherein said method is repeated sequentially by replacing said first plurality of probes with a subsequent plurality of each of the different unique probes within the entire library of 4 n n-mer probes.
5 . The method of claim 4 , wherein said sequential repetition of said method is conducted in a linear series of reactions.
6 . The method of claim 4 , wherein said sequential repetition of said method is conducted in a parallel series of reactions
7 . The method of claim 1 , wherein said recorded changes in electrical potential are processed using a computer algorithm to reconstruct the sequence of the biomolecule strand.
8 . The method of claim 1 , wherein said translocation is slowed down by introducing a viscous fluid into said first and second chambers.
9 . The method of claim 1 , wherein said translocation is slowed down by implementing a low temperature setup.
10 . The method of claim 1 , wherein a bead is attached to said hybridized strand and said translocation is slowed down through the use of optical tweezers.
11 . The method of claim 1 , wherein said step of hybridization of said biomolecule further comprises the steps of:
introducing said biomolecule to said first fluid chamber;
introducing a drop of a buffer solution containing said first plurality of probes into said first fluid chamber; and
allowing said probes to hybridize with said biomolecule within said first fluid chamber.
12 . The method of claim 1 wherein said first fluid chamber is a cis chamber having a cathode and said second fluid chamber is a trans chamber having an anode.
13 . The method of claim 1 wherein said membrane is a solid-state membrane having a nanopore formed therein.
14 . The method of claim 1 , wherein said nanopore has a diameter of between approximately 1 nm and 100 nm.
15 . The method of claim 1 , wherein said biomolecule strand of interest is selected from the group consisting of DNA, RNA and proteins.
16 . The method of claim 1 , said sequencing apparatus further including electrodes in said first and second fluid chambers, said electrodes configured to measure changes in electrical potential across said nanopore.
17 . The method of claim 1 , wherein the step of monitoring changes in electrical potential comprises monitoring changes in current across said nanopore.
18 . The method of claim 1 , wherein the step of monitoring changes in electrical potential comprises monitoring changes in capacitance across said nanopore.
19 . The method of claim 1 , wherein the step of monitoring changes in electrical potential comprises monitoring electron tunneling across said nanopore.