the analysis of the material produced by heterokaryons gave the following results : when ehrlich ascitic carcinoma cells infected with classical fowl plaque virus and labeled with 3h-uridine fused with uninfected unlabeled chicken fibroblasts , the heterokaryons , in addition to structures with the buoyant density of 1.29 g/ml typical for infected cells , also produced virus structures with a density of 1.25 g/ml and had a higher infectious activity ( 5.2 x 10 ( 7 ) pfu/ml ) than the structures produced by infected ehrlich cells ( 5.8 x 10 ( 6 ) pfu/ml ) ;
C0016030
fibroblasts
C0007634
cells