Patent ID: 6613517
Filing Date: 2003-09-02
Classification: C12Q

Abstract:
A method for screening a ligand for its ability to bind to a nucleotide sequence in a nucleic acid molecule, comprising:(a) providing a nucleic acid molecule having a first region and second region, adjacent to said first region, wherein said first region comprises a first site that is susceptible to modification by a modifying agent, wherein such modification is effective to block strand-directed duplication by a polymerase enzyme at said first site; (b) providing a ligand; (c) contacting said nucleic acid molecule with said ligand, under conditions suitable for sequence-dependent binding of said ligand to said nucleic acid molecule, to form a reaction mixture; (d) treating the reaction mixture of (c) with said modifying agent, under conditions wherein nucleic acid molecules comprising a ligand bound to said second region are substantially protected from modification at said first site, and nucleic acid molecules wherein a ligand is not bound to said second region are substantially modified at said first site; (e) after said treatment, contacting said nucleic acid molecule with said polymerase enzyme, under conditions wherein only unmodified nucleic acid strands are amplified, wherein said amplification indicates that said ligand binds to a nucleotide sequence in said second region.