Patent ID: 8889348

Claim:
A method for determining the nucleotide sequence of a single-stranded DNA comprising the steps of: (a) synthesizing a precursor of the single-stranded DNA as part of a double-stranded DNA using a single-stranded DNA template, a primer, a DNA polymerase, and all four nucleotides present in DNA, wherein each A or each G residue, but not both, comprise a first label bound to its respective base, and each C or each T residue, but not both, comprise a second label bound to its respective base; (b) denaturing the double-stranded DNA obtained in (a); (c) isolating the single-stranded DNA to be sequenced comprising the nucleotides containing the first label and the second label from the denatured double-stranded DNA; (d) reacting the single-stranded DNA isolated in (c) with first modifying groups which form bonds with the first labels and second modifying groups which form bonds with the second labels, so as to obtain the single-stranded DNA to be sequenced wherein each labeled nucleotide is conjugated to a modifying group; (e) passing the single-stranded DNA to be sequenced through a pore of suitable diameter by applying and electric field to the DNA: (f) determining an electronic signature for each nucleotide of the single-stranded DNA which passes through the pore; and (g) comparing each electronic signature determined in (f) with electronic signatures corresponding to each of A, G, C, and T or corresponding to the bases conjugated to the modifying group, so as to determine the identity of each such nucleotide, thereby determining the nucleotide sequence of the single-stranded DNA.