Essential oil dose not block IAV PR8 binding and entry to MDCK cells as determined by flow cytometry. MDCK cells were exposed to oil-treated (1:4,000 dilution) and untreated PR8. Viruses were allowed to bind to the cells at 4°C for 30 minutes, or allowed to bind and then internalize at 37°C for 30 minutes. Following the incubation of selected samples with sialidase treatment, viral NP was stained with the fluorescent dye Alexa Fluor 488. The percentage of cells exceeding the analytical gate was used to determine viral binding and internalization. The data are representative of three separate experiments.