Figure 5. Affinity measurements of selected RNA aptamers to gHA1.

(A) Each ³²P end-labeled RNA aptamer was incubated with gHA1, and the reaction sample was then filtered through a pre-wetted nitrocellulose membrane and applied to the double-filter dot-blot apparatus. The amounts of ³²P end-labeled RNA aptamers retained on the membrane in the presence of gHA1 were radioactively measured and quantified. Percentage binding to the gHA1 protein relative to the highest value is shown in the graph. (B) The immobilized gHA1 protein (0.5 µg) was incubated with each 3′-biotinylated RNA sample (30 ng) as indicated. After addition of streptavidin-conjugated HRP, the amount of the gHA1-aptamer complex was measured by absorbance reading at 450 nm.