Of 129 different arboviruses (134 strains) inoculated into cultures of the baby-hamster kidney-cell line BHK-21 (clone 13), all but five viruses produced cytopathic effect. The agents tested comprised members of 18 serogroups and a large number of ungrouped arboviruses. Comparative titrations of 10 viruses indicated that BHK-21 tissue culture, although slightly less sensitive than infant mice, could be of value as a routine assay system. Results were satisfactory in a limited series of BHK-21 tissue-culture neutralization tests.
A total of 31 arboviruses, 10 in the larger serogroups and 21 mostly ungrouped, was tested in tissue culture for hemadsorption of guinea-pig erythrocytes. Results were negative except for one ungrouped virus, both strains of which were shown to be a myxovirus. The applicability of the hemadsorption test as a screening method in field laboratories is discussed.