Figure 3.

Verification of aptamer pair binding. (A) Enzyme-linked oligonucleotide assay (ELONA) using ABA65, ABA92 or ABA109 as capture aptamers. As the detection aptamer, we used biotinylated ABA1; for controls, we used the same aptamer used for capture, a scrambled aptamer sequence or no detection aptamer. The three aptamers form pairs with ABA1 as shown by the high absorbance signals. (B) ELONA experiments show that these three aptamer pairs can detect unlabeled Ang2 in undiluted fetal bovine serum. In comparison, we observed only a modest signal when we used a scrambled aptamer sequence as the capture aptamer. All error bars were obtained from triplicate measurements.