Figure 4: PRNT for virus neutralization by anti-WNV Fab antibodies. The “virus control” represents the result obtained by infection of virus only without addition of antibody. The“Negative Serum Control”, “Mock Control”, and “Positive Serum Control” represent the results obtained by the mixtures of virus with no anti-WNV antibody serum, supernatant of lytic XL1-blue, and anti-WNV serum, respectively. The final concentration of antibody in the virus-antibody mixture is indicated.