Fig. 5.

Assessment of virus neutralizing activity of the anti-NS6 antibody. Two-fold serial dilutions (from 1:2 to 1:256) of the pre-immune serum, the hyperimmune anti-PDCoV serum and the anti-NS6 mouse serum were used to react with 100 TCID₅₀ of PDCoV. The mixtures were inoculated in LLC-PK1 cells for 48 h. (A) Numbers of PDCoV-infected cells were counted by IFA; (B) PDCoV RNA titers were measured by qRT-PCR, which were then compared between different treatments and represented by the relative infectivity (viral RNA copies of tested sera/viral RNA copies of pre-immune sera × 100%). Data represent mean values plus standard deviation (SD) of at least 3 replicates.