Fig. 3.

Growth phase dependence of 20A24P.A3 binding to live GAS cells. GAS 5448 cells were grown in THB media to the indicated optical densities at 600 nm (OD₆₀₀), then washed and photometrically adjusted to the same bacterial concentrations. Then, the binding of 5′-FAM versions of the 52-nt GAS aptamer 20A24P.A3 (black solid lines) to the bacteria was tested as described in Figs. 1 and 2. 5′-FAM 52-nt aptamer RAND-52 (dashed lines) and aptamer vehicle (gray solid) served as negative controls. FL-1 histogram overlays for the indicated stages of growth for a representative experiment of several performed are shown. For each experiment, the samples were run in duplicate yielding similar results