FIG 8.

Peak fractions of CHPV treated with PBS and not NHS retain infectivity. Gradient-purified CHPV treated with either PBS or NHS was subjected to ultracentrifugation, and the peak fractions showing reactivity to anti-CHPV antibodies were used for plaque reduction and immunofluorescence assays. Photograph of plaques in monolayers of Vero cells in 6-well plates infected with either the peak fractions of PBS or NHS-treated CHPV is shown in (A). The respective dilution (10⁻², 10⁻³, etc.) is marked within each well. Serum treatment resulted in marked reduction in the number of plaques compared to that of PBS treatment (A, bottom; B). The reduction in the number of plaques was statistically significant; ### denotes that no plaques were visualized, and *** denotes a P value of ≤0.001 (B). Immunofluorescence images showing the difference in infectivity of the peak gradient fractions of either PBS or NHS-treated samples. The scale bar in the images equals 10 μm.