KRAS and infection: Third, we analyzed the morphology of viral plaques by immunostaining cell monolayers at 5 days post-infection with a polyclonal rabbit α-JEV NS3 antiserum in the case of the parental JEV and three chimeric JEV/ZIKVs, or a polyclonal rabbit α-ZIKV NS1 antiserum in the case of the three original ZIKVs (Figure 2C).