The CEHs were seeded in 6 or 96-well plastic culture plates (Nunc, Denmark) at a density of 105/well in 2 mL (6-well) or
200 μL (96-well) medium 199 supplemented with 2 mM glutamine, 1.75 mM HEPES, 5 mM NaHCO3, 10% FBS, 100 IU/mL penicillin and 100 μg/mL streptomycin. The CEHs were incubated at 37 °C in a water-saturated atmosphere of 95% air and 5% CO2, and allowed 24 h acclimation before treatment.