2.9 Neutralizing Antibody Titers
Serum samples were examined for anti-FMDV neutralizing Abs as described before (V. Quattrocchi et al., 2014). Briefly, serial dilutions of complement-inactivated sera were incubated for 1 h at 37°C with 100 TCID50 of infective FMDV. Then virus-serum mixtures were seeded on BHK-21 monolayers. After 40 min at 37°C, fresh DMEM /2% FCS was added to the monolayers, which were incubated at 37°C, under 5% CO2. Cytopathic effects were observed after 48 h.