Dna sequencing by nanopore using modified nucleotides

Abstract

This invention provides a process for sequencing single-stranded DNA by employing a nanopore and modified nucleotides.

1 - 17 . (canceled) 
     
     
         18 . A method for determining the nucleotide sequence of a single-stranded DNA comprising the steps of:
 (a) synthesizing a double-stranded DNA using the single-stranded DNA as template, a primer, a DNA polymerase, and all four nucleotides A, G, C and T;   (b) determining using a nanopore an electronic signature corresponding to each A, G, C and T being polymerized using the single-stranded DNA as a template; and   (c) comparing each electronic signature determined in (b) with electronic signatures corresponding to each of A, G, C and T so as to determine the identity of each such nucleotide,   thereby determining the nucleotide sequence of the single-stranded DNA.   
     
     
         19 . The method of  claim 18 , wherein the nanopore has a diameter of from about 1 nm to about 5 mm. 
     
     
         20 . The method of  claim 18 , wherein the nanopore has a diameter of from about 1 nm to about 3 nm. 
     
     
         21 . The method of  claim 18 , wherein the nanopore has a diameter of about 1 nm, 2 nm, 3 nm, 4 nm or 5 nm. 
     
     
         22 . The method of  claim 18 , wherein each A and each T nucleotide comprises a modifying group. 
     
     
         23 . The method of  claim 18 , wherein each G and each C nucleotide comprises a modifying group. 
     
     
         24 . The method of  claim 18 , wherein each A and each C nucleotide or each G and each T nucleotide comprises a modifying group. 
     
     
         25 . The method of  claim 18 , wherein A, G, C and T nucleotides of said single-stranded DNA have an order of bulkiness that is T>A>G>C.