aptamer
noun
ap·ta·mer
| \ ˈap-tə-mər
\
\
Medical Definition of aptamer
: a short segment of DNA, RNA, or peptide that binds to a specific molecular target (such as a protein)
This aptamer works by binding and blocking a major molecule involved in the body's blood-clotting reaction, called thrombin.— Debora MacKenzie, New Scientist, 6 Oct. 2006 Aptamers … are isolated by … the repetitive screening of large pools of randomized molecules for those that bind best to a target. — Chemical & Engineering News, 15 Mar. 1993