Aptamers: Analytical Tools for Viral Components

Aptamers are oligonucleotides obtained by a combinatorial method from randomly synthesized libraries. They usually exhibit strong affinity and high specificity of interaction with a predetermined target. They actually rival antibodies and are of interest for multiple purposes, notably for diagnostic. As aptamers can be easily immobilized on a number of surfaces, they can be used for detecting the presence of viral constituents, RNA or proteins. The detection can be carried out in a number of different formats (fluorescence, SPR, etc.). We raised aptamers against RNA motifs of the human immunodeficiency virus or of the hepatitis C virus. Such aptamers display a very high specificity of recognition, surpassing that of complementary oligonucleotides as they recognize the 3D shape and not only the primary sequence. We also raised aptamers against the M1 protein of the influenza virus allowing its detection. We took advantage of fluorescence transfer for monitoring interactions between aptamers and their cognate ligand immobilized on particles. This strategy could be used either for screening libraries or for evaluating the presence of an analyte.