Patent ID: 7582421

Claim:
A method for detecting a single nucleotide polymorphism in a sample nucleic acid using an electronically addressable microchip having a plurality of test sites, wherein each of the test sites comprises an individually controllable electrode covered by a permeation layer, the method comprising: providing a sample nucleic acid suspected of containing a single nucleotide polymorphism; electronically biasing the sample nucleic acid to a test site of the plurality of test sites on the microchip, and concentrating the sample nucleic acid at the test site; immobilizing the sample nucleic acid onto the test site; electronically hybridizing a mixture comprising a first probe with a label selected from the group consisting of fluorescent label, colorimetric label, and chemiluminescent label, and a second probe with a label selected from the group consisting of fluorescent label, colorimetric label, and chemiluminescent label to the sample nucleic acid , wherein the first probe is perfectly complementary to the sample nucleic acid and contains a nucleotide perfectly complementary to the nucleotide at the site of the polymorphism, and forms a first hybridized complex, and the second probe is complementary to the sample nucleic acid and contains a nucleotide which forms a mismatch with the nucleotide at the site of the polymorphism, and forms a second hybridized complex, wherein the label of the first probe and the label of the second probe are different; subjecting the first and second hybridized complexes to destabilizing conditions sufficient to cause the first probe to dissociate from the first hybridized complex or the second probe to dissociate from the second hybridized complex if there is at least one base-pair mismatch between the first probe or the second probe and the sample nucleic acid; and detecting the first or second hybridized complex following the subjecting step by determining a signal intensity from the label of the first probe of the first hybridized complex or a signal intensity from the label of the second probe of the second hybridized complex, wherein the single nucleotide polymorphism in the sample nucleic acid is detected if the signal intensity from the label of the first probe of the first hybridized complex is present.