FIG 3.

CHIKV strains bind directly to heparin and chondroitin sulfate. Serial dilutions of each CHIKV strain, quantified by genome number, were adsorbed to wells of avidin-coated ELISA plates bound with biotinylated heparin (A) or biotinylated CS (B). PBS was adsorbed to wells coated with heparin and CS as a negative control. Following washes to remove unbound virus, virus binding was detected using a mouse monoclonal anti-CHIKV E2 antibody (CHK-187), secondary goat anti-mouse HRP-conjugated antibody, and TMB substrate. Absorbance was measured at 450 nm for duplicate wells from three independent experiments. The dashed line indicates background levels of binding, as determined using PBS control wells. Error bars indicate SEM. Data were fit using a nonlinear regression curve.