Methods for electronic stringency control for molecular biological analysis and diagnostics

A method for electronically controlling hybridization of DNA from a solution containing specific binding and non-specific binding DNA sequences to a binding location, comprising the steps of:

• placing the solution in contact, under suitable conditions such that hybridization is permitted, with a first binding location including a first underlying electrode, and a second binding location including a second underlying electrode;
• placing said first binding location at a positive potential, relative to said second binding location, concentrating DNA on said first location surface;
• and
• placing said first binding location at a negative potential, relative to said second binding location, wherein said negative potential or current is sufficient to remove the non-specifically bound DNA sequences from said first binding location, but not sufficient to remove the specifically bound DNA sequences.

A method for electronically controlling hybridization of DNA from a solution containing specific binding and non-specific binding DNA sequences to first and second binding locations, comprising the steps of:

• placing the solution in contact, under suitable conditions such that hybridization is permitted, with the first, second, and a third locations;
• placing said first and second binding locations at a positive potential and said third location at a negative potential, concentrating DNA on said first and second locations;
• placing said first and second specific binding locations at a negative potential and said third location at a positive potential;
• and
• placing said first and second binding locations at negative potentials, relative to said third location, wherein said negative potential or current is sufficient to remove the non-specifically bound DNA from said first and second locations, but not sufficient to remove the specifically bound DNA sequences.

A method for electronically controlling hybridization of DNA from a solution containing specific and non-specific DNA sequences to a first binding location and then to a second specific binding location, comprising the steps of:

• placing the solution in contact, under suitable conditions such that hybridization is permitted, with said first, second, and a third location;
• placing said first binding location at a positive potential and said second binding location at a negative potential, concentrating DNA on said first location;
• placing said first binding location at a negative potential and said second binding location at a positive potential, concentrating DNA on said second location;
• and
• placing said first and second binding locations at negative potentials, relative to said third binding location, wherein said negative potential or current is sufficient to remove the non-specifically bound DNA from said first and second locations but not sufficient to remove the specifically bound DNA.

A method for improved stringency control of nucleic acid hybridization reactions comprising the steps of:

• transporting reactants or analytes to a microlocation containing attached specific binding entities,
• concentrating the reactants or analytes at one or more specific microlocations where hybridization may occur with the specific binding entities,
• selectively removing unreacted and non-specifically bound components from microlocations where hybridization has occurred by raising the electric potential,
• varying the repulsive force by applying a signal which varies in time sequence in both magnitude and sign at the microlocation so as to vary the detectable characteristic of the microlocation, and
• detecting the state of hybridization.