Patent ID: 8680017

Claim:
A method of identifying nucleic acid aptamers for a target molecule comprising: obtaining an at least partially purified target molecule; obtaining a nucleic acid ligand library, said nucleic acid ligand library comprising a plurality of nucleic acid molecules; mixing the target molecule with the nucleic acid ligand library such that the target molecule binds to one or more aptamers present in the nucleic acid ligand library; digesting unbound nucleic acid molecules with one or more nucleases; separating the nucleic acid molecules bound to the target molecule from at least a portion of the unbound nucleic acid molecules, wherein said separation is accomplished by: a) digesting unbound nucleic acid molecules; or b) digesting unbound nucleic acid molecules in combination at least one physical separation means; disassociating the target molecule from the one or more nucleic acid molecules; and amplifying separated nucleic acid molecules; wherein the nucleic acid ligand library comprises a plurality of nucleic acid molecules comprising the sequence 5′-Z x —N x —Z′ x -3′, where N is A, G, C, T or, in the case of RNA, U, and where x is an integer from about 5 to about 100, or larger, where Z and Z′ is A, G, C, T or, in the case of RNA, U, and where Z x and Z′ x are complementary, or substantially complementary, to each other, and where Z x and Z′ x form secondary structure; wherein the nucleic acid ligand library comprises a plurality of nucleic acid molecules comprising the sequence 5′-TTTGGGGGGGGTTTTTTTTGGG-N x -CCCAAAAAAAACCCCCCCCAAA-3′ (SEQ ID NOs: 1 and 2, respectively), where N is A, T, G, or C, where N is A, G, C, T or, in the case of RNA, U, where x is an integer from about 5 to about 100, or larger, where the sequence 5′-TTTGGGGGGGGTTTTTTTTGGG-3′ (SEQ ID NO:1) is the Z x structure, and where the sequence 5′-CCCAAAAAAAACCCCCCCCAAA-3′ (SEQ ID NO:2) is the complementary Z′ x structure.