Effects of CHLA and PUG against virus binding analyzed by ELISA. Different cell monolayers were pre-chilled at 4°C for 1 h and then inoculated with the respective viruses in the presence or absence of various concentrations of test compounds at 4°C for an additional 2 h. Following the virus binding period, the cell monolayers were washed to remove unadsorbed virus, subsequently fixed with 4% PFA, and then blocked with 5% BSA. ELISA was performed with virus-specific antibodies and HRP-conjugated IgG, followed by development with a TMB substrate kit. The absorbance was immediately determined at 450 nm and values are expressed as the fold change of absorbance relative to the mock infection control (cells + DMSO), which is indicated by the dashed line. (A) Schematic of the experiment with the virus concentration (MOI) and test compound treatment time (i) indicated for each virus in the associated table. Analyses for (B) HCMV, (C) HCV, (D) DENV-2, (E) MV, and (F) RSV are indicated in each additional panel. Results shown are means ± SEM from three independent experiments. See text for details.