Patent ID: 6716583
Filing Date: 2004-04-06
Classification: A61K,B82Y,C07H,C07K,C12N,C12Q,C40B,F02B,G01N

Abstract:
A method for preparing an improved nucleic acid ligand, said nucleic acid ligand capable of binding to and altering the function of a target molecule, wherein said improvement is produced by modifying a nucleic acid ligand to have enhanced target function altering activity, said method comprising:a) contacting a candidate mixture with the target, wherein nucleic acids having an increased affinity to the target relative to the candidate mixture may be partitioned from the remainder of the candidate mixture; b) partitioning the increased affinity nucleic acids from the remainder of the candidate mixture; c) amplifying the increased affinity nucleic acids to yield a ligand-enriched mixture of nucleic acids; d) repeating steps a)-c) as necessary to identify a nucleic acid ligand of said target; e) determining the target function altering activity of said nucleic acid ligand of step d); f) modifying the nucleic acid ligand of step d), wherein said modifying comprises adding, deleting, or substituting nucleotide residues, wherein said residues may be chemically modified, and/or chemically modifying said nucleic acid ligand; and g) determining whether the modified nucleic acid ligand of step f) has enhanced target function altering activity relative to the target function altering activity of the nucleic acid ligand of step e), whereby said improved nucleic acid ligand may be prepared.