In vitro selection for nucleic acid aptamers

A method of identifying or producing an aptamer capable of binding to a target molecule, wherein the method comprises:

• a) providing a plurality of circular nucleic acid molecules, wherein the plurality of circular nucleic acid molecules comprises oligonucleotides having at least one random nucleotide domain flanked by a 5′-end primer region and a 3′-end primer region;
• b) contacting the plurality of circular nucleic acid molecules with a bare solid support;
• c) collecting unbound circular nucleic acid molecules;
• d) contacting the unbound circular nucleic acid molecules with solid support coated with the target molecule to form a complex comprising bound circular nucleic acid molecules;
• e) optionally washing the complex;
• f) eluting the bound circular nucleic acid molecules from the complex;
• and
• g) amplifying the eluted circular nucleic acid molecules by polymerase chain reaction (PCR).