Figure 2
Representative pictures showing virus neutralizing antibody response in PEDV infected sows plasma samples. A Fifty TCID50 of virus was used in the NA assay which showed appreciable quantity of infected cells by immunofluorescence (IFA) assay at 24 h post-infection. B Each of representatives experimental plasma sample of PEDV uninfected and infected sows were twofold serially diluted from 1:8 to 1:1024 and mixed with 50 TCID50 of PEDV; and Vero cells treated with that mixture were subjected to IFA and examined under 200×magnification. VN titer was expressed as the reciprocal of the highest dilution ratio of test samples that caused greater than 90% reduction in virus induced fluorescence foci units compared to that of virus control.