the stabilities of b77 avian sarcoma virus intracellular rnas were compared to the stability of the total cellular poly ( a ) -containing rna by labelling infected chicken embryo fibroblasts with [ 3h ] uridine for 15 h , adding actinomycin d ( 1 microgram per ml ) to block further transcription of viral rna , and selecting virus-specific rna from the total cellular poly ( a ) -containing rna at 3 hourly intervals .
C0016030
fibroblasts
C0007634
cellular