Screening ssDNA aptamers against HIV P24 antigen using agarose beads as carriers

In this study, carboxylated agarose beads were used as screening carriers combined with the subtractive systematic evolution of ligands by exponential enrichment (SELEX) technology to obtain an ssDNA secondary library, which could specifically bind to HIV P24 antigen after nine screening rounds from a random ssDNA library. An electrophoretic mobility shift assay (EMSA) and quantitative real-time PCR assay (RT-qPCR) was performed to monitor in real-time the binding specificity of the ssDNA secondary library to the HIV P24 antigen. The obtained ssDNA secondary library was converted to the corresponding dsDNA library, ligated to a PMD18-T vector, and transformed into E. coli DH5α and sequenced. The results demonstrated that after nine rounds of screening, two aptamer sequences specifically bound to the HIV P24 antigen were obtained