Selective Evolution of Ligands by Exponential Enrichment to Identify RNA Aptamers against Shiga Toxins

Figure 3

Flow cytometry analysis of HeLa cells treated with Stx2 and aptamers. Flow cytometry analysis showed that, in absence of any aptamer, Stx2-AF labeled ~78% of the HeLa cells, and in presence of an unrelated control aptamer, Stx2-AF labeled 76% cells. Most of the Stx2-specific aptamers (mA_Apt1, mB_Apt23, mC_Apt41, mD_Apt46, pA_Apt1, and pCApt22) inhibited Stx2 binding weakly as approximately 50% of HeLa cells were labeled in the presence of these aptamers. Similar to the unrelated control aptamer, the remaining 2 Stx2-binding aptamers (pB_Apt14 and pD_Apt25) did not inhibit Stx2 binding. This experiment was repeated twice with similar results.