Apparatus and methods for detecting nucleic acid in biological samples

Abstract

There are disclosed apparatus and methods for the field-assisted acceleration of biological processes involving charged entities, including in particular the detection of target DNA in a biological sample. A reaction cell is provided with a dielectric surface, and a field is generated by inducing charge-separation in the dielectric material by applying a potential to an electrode in contact with the dielectric material.

1 . Apparatus for detecting target nucleic acid in a sample, comprising a substrate formed with at least one reaction cell, wherein said reaction cell includes an attachment surface formed of a dielectric material for the attachment of nucleic acid capture probes, and wherein a metal electrode is provided in direct contact with said dielectric material. 
     
     
         2 . Apparatus as claimed in  claim 1  wherein said electrode is in contact with a side of said dielectric material opposite from said attachment surface. 
     
     
         3 . Apparatus as claimed in  claim 1  wherein said dielectric material is an oxide. 
     
     
         4 . Apparatus as claimed in  claim 3  wherein said dielectric material is selected from the group consisting of Al 2 O 3 , SiO 2  and Ta 2 O 5 . 
     
     
         5 . Apparatus as claimed in  claim 1  wherein said electrode is formed of aluminum. 
     
     
         6 . Apparatus as claimed in  claim 1  wherein said dielectric material comprises Al 2 O 3  and said electrode is formed of aluminum. 
     
     
         7 . Apparatus as claimed in  claim 1  comprising a multilayer structure comprising a first base layer, a second insulating layer formed on said base layer, a third layer formed on said insulating layer and comprising patterned conductive regions defining at least one metal electrode, and a fourth layer comprising at least one region of dielectric material, wherein each said metal electrode in said third layer is covered by a region of dielectric material in said fourth layer. 
     
     
         8 . Apparatus as claimed in  claim 6  wherein the patterned conductive regions of said third layer are separated by regions formed of dielectric material. 
     
     
         9 . Apparatus as claimed in  claim 6  wherein said regions of dielectric material in said fourth layer are separated by regions of a passivation material. 
     
     
         10 . Apparatus as claimed in  claim 8  wherein said regions of passivation material extend over the edges of said regions of dielectric material to define said reaction cells. 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . A method of performing field-assisted hybridization in the detection of nucleic acid targets from a sample, comprising the steps of providing a reaction cell having an attachment surface formed of a dielectric material, providing a metal electrode in direct contact with said dielectric material, attaching nucleic acid capture probes to said attachment surface, adding the sample to said reaction cell, and providing an electrical potential to said electrode. 
     
     
         14 . A method as claimed in  claim 13  wherein said electrode is provided in contact with a surface of said dielectric opposite from said attachment surface. 
     
     
         15 . A method as claimed in  claim 13  wherein said electrical potential is a continuously applied potential. 
     
     
         16 . A method as claimed in  claim 13  wherein said electrical potential is applied as a series of pulses. 
     
     
         17 . A method as claimed in  claim 13  wherein said sample comprises biological substances. 
     
     
         18 . A method of attracting or repelling electrically-charged entities to or from a surface of a reaction cell when performing a biological reaction, comprising the steps of providing a dielectric material as said surface, and generating an electrical field by inducing charge-separation in said dielectric material. 
     
     
         19 . A method as claimed in  claim 18  wherein charge-separation in said dielectric material is induced by placing an electrode in direct contact with said dielectric material and applying a potential to said electrode. 
     
     
         20 . A method as claimed in  claim 19  wherein a continuous potential is applied to said electrode. 
     
     
         21 . A method as claimed in  claim 19  wherein a pulsed potential is applied to said electrode. 
     
     
         22 . A method as claimed in  claim 19  wherein said electrode is placed in contact with a surface of the dielectric material opposite from the surface to which the charged entities are to be attracted to or repelled from. 
     
     
         23 . (canceled) 
     
     
         24 . (canceled) 
     
     
         25 . (canceled) 
     
     
         26 . (canceled)