Patent ID: 6582921
Filing Date: 2003-06-24
Classification: B01J,B82B,B82Y,C07B,C07H,C12Q,C40B,Y02A,Y10S

Abstract:
A method of detecting one or more nucleic acid targets, each having at least two portions comprising:providing a substrate having one or more types of first nanoparticles attached thereto, each type of first nanoparticles having oligonucleotides attached thereto, the oligonucleotides of each type of first nanoparticles having a sequence complementary to a first portion of the sequence of a specific nucleic acid target to be detected; contacting one or more nucleic acid targets with the first nanoparticles attached to the substrate under conditions effective to allow hybridization of the oligonucleotides on the first nanoparticles with said nucleic acid targets; providing one or more types of second nanoparticles having oligonucleotides attached thereto, the oligonucleotides of each type of second nanoparticles having a sequence complementary to one or more other portions of the sequence of said nucleic acid target to be detected; contacting said nucleic acid targets bound to the substrate with one or more types of second nanoparticles under conditions effective to allow hybridization of the oligonucleotides on the second nanoparticles with said nucleic acid targets; and observing a detectable change, wherein in the presence of said one or more nucleic acid targets and under hybridization conditions, said nanoparticles having oligonucleotides bound thereto form complexes with said nucleic acid targets, the resulting nanoparticle-nucleic acid target complexes having a sharp melting profile and an increased melting temperature, relative to a melting profile and a melting temperature of analogous complexes formed with said nucleic acid targets and an unlabeled or fluorophore-labeled oligonucleotides having a sequence identical to the oligonucleotides bound to the nanoparticles, to allow for selective discrimination of a single nucleotide insertion, deletion, or mismatch in said nucleic acid targets under stringent hybridization conditions, whereby the stringency of said hybridization conditions are higher than those possible for said analogous complexes.