Each well was washed with 200 μl of 154 mM NaCl, 0.05% Tween-20 (wash buffer) for 3 min, three times. Antigen was blocked with 200 μl/well of 3% BSA in coating buffer at 37 °C for 2 h. Plates were washed with 200 μl/well of wash buffer for 3 min, three times.