aptamer

1. (biochemistry, genetics) Any subsequence of nucleic acid, selected from a large random sequence-pool, used to bind to a specific target molecule.Examples: "Aptamers are oligomers of RNA or DNA that spontaneously fold into specific three-dimensional shapes that can bind defined targets. The specificity of the shape of the binding site arises from the base sequence of the aptamer, which determines the base-pairing pattern of the oligomer."; "2009, Corinne Ravelet, Eric Peyrin, Chapter 10: Aptamers in Affinity Separations: Stationary Separation, Yingfu Li, Yi Lu (editors), Functional Nucleic Acids for Analytical Applications, page 271, The use of DNA or RNA aptamers as tools in analytical chemistry is a very promising field of research because of their capabilities to bind specifically the target molecules with an affinity similar to that of antibodies."; "The field of aptamer research is also more targeted, with many more catalytic aptamers being examined rather than for binding alone."