High resolution dna detection methods and devices

Abstract

The present invention provides methods and devices for detecting a target nucleic acid molecule. A set of oligonucleotide probes integrated into an electric circuit, where the oligonucleotide probes are positioned such that they cannot come into contact with one another, are contacted with a sample. If the sample contains a target nucleic acid molecule, one which has sequences complimentary to both probes, the target nucleic acid molecule can bridge the gap between the probes. The resulting bridge can then carry electrical current between the two probes, indicating the presence of the target nucleic acid molecule.

What is claimed is: 
     
         1 . A device for detecting the presence of a target nucleic acid molecule, comprising:
 two electronic leads, where an end of a first lead is located near an end of second lead but where the leads are not in contact,   one or more sets of two oligonucleotide probes attached to the electronic leads, where the oligonucleotide probes are positioned such that the probes can not come into contact with one another and such that a target nucleic acid molecule, which has two sequences, a first sequence complimentary to a first probe attached to the first lead and a second sequence complimentary to a second probe attached to the second lead, can bind to both probes concurrently completing an electrical circuit, when the target nucleic acid molecule is present,   a fluidic channel for introducing a reagent to coat the target nucleic acid molecule with a metal conductor,   an electric potential for generating a current flow through the electrical circuit,   a computer for detecting an electrical current and correlating the presence or absence of an electrical current to the presence or absence of the target nucleic acid molecule;   wherein a bridged probe having an electrical current flowing through the two electrical leads and a target nucleic acid molecule denotes the presence of the target nucleic acid molecule; and an unbridged probe lacks an electrical current denoting the absence of the target nucleic acid molecule.   
     
     
         2 . The device according to  claim 1 , further comprising:
 a chamber for treating a sample to release nucleic acid molecules from a sample.   
     
     
         3 . The device according to  claim 1 , wherein the device contains proteins for processing the sample. 
     
     
         4 . The device according to  claim 3 , wherein the protein is selected from the group consisting of a ligase, protease, restriction endonuclease, nuclease, or nucleic acid binding protein. 
     
     
         5 . The device according to  claim 3 , wherein the protein is a thermostable protein. 
     
     
         6 . The device according to  claim 1 , wherein the nucleic acid molecule is DNA. 
     
     
         7 . The device according to  claim 1 , wherein the nucleic acid molecule is RNA. 
     
     
         8 . The device according to  claim 1 , wherein the metal conductor is silver. 
     
     
         9 . The device according to  claim 1 , wherein the metal conductor is gold. 
     
     
         10 . The device according to  claim 1 , further comprising:
 a chamber containing nucleases for contacting the target nucleic acid after binding with the probes.   
     
     
         11 . The device according to  claim 1 , further comprising:
 heating elements for heating the sample.   
     
     
         12 . The device according to  claim 1 , wherein the probes are complimentary to sequences from the genetic material of a pathogenic bacteria. 
     
     
         13 . The device according to  claim 12 , wherein the pathogenic bacteria is a biowarfare agent. 
     
     
         14 . The device according to  claim 12 , wherein the pathogenic bacteria is a food borne pathogen. 
     
     
         15 . The device according to  claim 1 , wherein the probes are complimentary to sequences from the genetic material of a virus. 
     
     
         16 . The device according to  claim 1 , wherein the probes are complimentary to sequences from the genetic material of a human. 
     
     
         17 . The device according to  claim 16 , wherein one or both of the probes has a sequence which is complimentary to a sequence having a polymorphism, where the base or bases complimentary to the polymorphism are located at the end of the probe. 
     
     
         18 . A device for detecting the presence of a target nucleic acid molecule, comprising:
 two electronic leads, where an end of a first lead is located near an end of second lead but where the leads are not in contact,   one or more sets of two oligonucleotide probes attached to the electronic leads, where the oligonucleotide probes are positioned such that the probes can not come into contact with one another and such that a target nucleic acid molecule, which has two sequences, a first sequence complimentary to a first probe attached to the first lead and a second sequence complimentary to a second probe attached to the second lead, can bind to both probes concurrently completing an electrical circuit, when the target nucleic acid molecule is present,   a first microfluidic channels for contacting the probes with a sample which may have the target nucleic acid molecule to permit the target nucleic acid molecule, if present in the sample, to bind to both probes,   a second fluidic channel for introducing a reagent to coat the target nucleic acid molecule with a metal conductor,   an electric potential for generating a current flow through the electrical circuit,   a computer for detecting an electrical current, the electrical current indicating the presence of the target nucleic acid molecule in the sample and no electrical current indicating the lack of the target nucleic acid molecule in the sample.