SEROLOGIC STUDIES OF AFRICAN HORSE-SICKNESS VIRUS WITH EMPHASIS ON NEUTRALIZATION TEST IN TISSUE CULTURE.

In place of mice, monkey kidney stable (MS) cell cultures were used successfully in serologic studies of African horse-sickness virus.The maintenance medium containing 2% serum was chosen as the virus diluent. Maximum neutralization occurred after 1-hour incubation at 37 C., and maintained the same titer during an additional 4-hour incubation period. No significant difference was observed between neutralization titers titrated using the same antiserum mixed with two different passage levels of virus. Rabbit and guinea pig antiserums prepared using virus grown in MS cell cultures had antibody titer as high as those prepared in the same manner using mouse brain suspension. African horse-sickness virus strains isolated in Asia were serologically identified using a standard neutralization technique in tissue culture. All the strains were closely related to each other and all had antigenic similarity to Type 6 virus (strain 114).