CHARACTERIZATION FOLLOWING SELECTED ADSORPTION PROCEDURESA

SUMMARY The B1 and DK 1155 strains of Newcastle disease virus were adsorbed and subsequently eluted from chicken brain cells and erythrocytes. As compared with untreated virus which was physically manipulated in parallel, the following observations were made. The hemagglutination activity of DK 1155 virus was readily adsorbed by brain cells; however, the activity of B1 virus similarly treated was not altered. The embryo pathogenicity of the two viruses was not influenced by contact with chicken brain cells; however, the activity of each virus was markedly reduced following contact with chicken erythrocytes. Erythrocyte-eluted virus was highly active. The B, strain of virus had no demonstrable intracerebral pathogenicity in day-old chicks. The intracerebral pathogenicity of DK 1155 virus was not affected by contact with chicken brain cells; however, the activity of the virus was significantly reduced following contact with chicken erythrocytes. Erythrocyte-eluted virus was highly active. Differences in intracerebral pathogenicity were significant between Newcastle disease nonimmune and immune chicks. There is no relationship between the hemagglutination activity of a Newcastle disease virus and its embryo and intracerebral pathogenicity.