Detection of NDV genes and proteins in the SW480P cells. (A) RT-PCR analysis on DNA samples of SW480 and SW480P cells infected and mock infected with NDV. A DNA band with a size of 1.7 kb appeared in selected samples. (B) Immunofluorescent analyses of the infected and control cells using a monoclonal antibody against the NP protein of NDV. A speckled pattern of green antigen staining was visible in the cytoplasm of cells.