Chick embryo fibroblasts concentration

Certain quassinoids display in vitro antiviral activity, namely against the oncogenic Rous sarcoma virus 79). This test is performed as follows Chick-embryo fibroblasts are infected by a known amount of the virus which transforms the morphology of the cells into foci. A number of quassinoids inhibit this transformation at concentration ranging from 0.15 to 1 pg/ml, without having toxic effects on normal cells. Some of the results are shown in Table 2. 

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