Patent ID: 6858390

Claim:
A method for binding a ligand, said method comprising: providing an aptamer comprising at least two parallel or antiparallel heteropolymeric nucleobase-containing sequences bonded together by Watson-Crick complementary base interaction or by homologous base interaction, wherein: (a) said aptamer comprising a duplex, and said at least two sequences are bonded together by Watson-Crik complememtary base interaction with parallel directionality: (b) said aptamer comprises a duplex, and at least two sequences are bonded together by homologous base interaction with paralleli or antiparallel directionally: (c) said apatmer comprises a triplex, and said at least two sequences are bonded together by Watson-Crik complementary base interaction with parallel or antiparallel directionity: (d) said aptamer comprises a triplex, and said at least two sequences are bonded together by homologeous base interaction with parallel or antiparallel directionality; (e) said aptamer comprises a quadruplex, and said at least two sequences are bonded together by Watson-Crik complementary base interaction with parallel or antiparallel directionality and do not rely on Hoogsteen bonding and GG quartets for maintence of complex structure or (f) said aptamer comprises a quadruplex, and said at least two sequences are bonded together by homologous base interaction with parallel or antiparallel directionality and do not rely on Hoogsteen bonding and GG quartets for maintenance of complex structure; and contacting said aptamer with said ligand to bind said ligand to said aptamer by interaction other than by Watson-Crik base pairing of nucleobase to nucleobase.