1) Biotechnology 
Aptamers (from the Latin aptus - fit, and Greek meros - part) are oligonucleic acid or peptide molecules that bind to a specific target molecule. Aptamers are usually created by selecting them from a large random sequence pool, but natural aptamers also exist in riboswitches. Aptamers can be used for both basic research and clinical purposes as ma...
<molecular biology> A double stranded DNA or single stranded RNA molecule that bind to specific molecular targets, such as a protein or metabolite. ... (13 Oct 1997) ... 
Short strands of DNA or RNA that are designed to bind to certain target molecules.