Figure 3

Antiviral assay strategies with drugs on different stages of virus infection. (A) Simultaneous treatment assay: MDCK cells were inoculated with PR8 treated with suxiaoganmaojiaonang (S, 4.375 mg/ml), dandelion (D, 2.5 mg/ml), ostalmivir (O, 0.3 mg/ml), or untreated with drugs (negative control) for 1 h, the media was removed and replaced by DMEM without any drugs; (B) Post treatment assay: Influenza viruses (1 × 10⁶ PFU) were inoculated in MDCK cells. After 1 h, viruses were removed and MDCK cells were treated with suxiaoganmaojiaonang (S, 4.375 mg/ml), dandelion (D, 2.5 mg/ml), ostalmivir (O, 0.1 mg/ml) or untreated with drugs (negative control). The cultures were incubated for 16 h at 37°C under 5% CO₂ atm. The yield of progeny viruses in MDCK supernatant was determined by plaque assay. Each concentration of drugs was assayed two times in triplicate.