Patent ID: 7935481

Claim:
A method of determining the identification of nucleotide(s) at a first detection position in a first domain of a target sequence, said target sequence comprising said first domain and a second domain, said method comprising: a. providing an electrode with a covalently attached capture probe, wherein said capture probe has a sequence substantially complementary to said second domain of said target sequence; b. contacting said electrode with: (i) said target sequence; (ii) a first label probe substantially complementary to said first domain, comprising a first nucleotide at an interrogation position and a first electron transfer moiety (ETM) with a first redox potential; (iii) a second label probe substantially complementary to said first domain, comprising a second nucleotide at said interrogation position and a second ETM with a second redox potential; under conditions wherein if said nucleotide at said interrogation position is perfectly complementary to said detection position, hybridization of said probe(s) occurs; and c. detecting the presence of said first and/or second ETM to determine the nucleotide(s) at said detection position.