Fig. 9.

BrU label is not detected if cells are treated with actinomycin D or RNAse. HeLa cells were either mock-infected or infected with HSV-1 KOS for 7 h at which time cells were incubated with culture medium containing 4 mM BrU for 30 min under conditions of no drug or RNAse treatment. In samples treated with actinomycin D, 10 μg/ml actinomycin D was added with BrU to stall transcription. In samples treated with RNAse, an RNAse cocktail (Ambion) was added after permeabilizing the cells. Cells were treated for 30 minutes at 30°C. Cells were fixed and immunofluorescent staining was performed with anti-BrU antibody conjugated to Texas red. Cells were also stained with anti-ICP4 antibody and DAPI.