Patent ID: 8236570

Claim:
A method for identifying a nucleic acid ligand of a target molecule from a candidate mixture of nucleic acids, the method comprising: incubating a candidate mixture of nucleic acids with a plurality of target molecules to form nucleic acid/target molecule complexes, wherein the target molecules are bound to beads; and eluting the nucleic acids from the complexes that have been loaded onto an HPLC column by applying an HPLC gradient profile, wherein nucleic acids with the greatest affinity for the target molecule elute at an end portion of the gradient profile and nucleic acids with a lesser affinity for the target molecule and nucleic acids with no affinity for the target molecule elute prior to the end portion of the gradient profile, and wherein the gradient profile comprises a linearly increasing concentration of the target molecule and the end portion of the gradient profile comprises a linearly increasing concentration of the target molecule and a linearly increasing concentration of a chaotropic agent.