Fig. 3. Location of viral nucleic acids and nucleic acid synthesis relative to UBF in adenovirus-infected cells. (A) A fluorescence in situ hybridisation analysis shows a cell 18 hours post-infection with adenovirus adjacent to an uninfected cell which serves as a control for the probe. The location of UBF is shown in green, the DIG-labelled adenovirus DNA is shown in red and the nucleus is revealed by DAPI staining, and is in blue. (B) At 18 hours post-infection, cells were treated with FU to reveal sites of RNA synthesis. UBF is in green, the newly synthesised RNA is in red and viral DBP is in blue. (C) The cells were labelled at 18 hours post-infection with BrdU followed by a chase period of 2 hours. UBF is in green and BrdU is in red. As stated in the Materials and Methods the cells were pretreated with HCl to reveal the location of all the incorporated label, both ssDNA and dsDNA. (D) The pulse period was short, there was no chase and the HCl treatment was omitted. Again, UBF is in red, BrdU is in green and DAPI is in blue. All images are of a single focal plane approximately 0.3 µm depth; bar, 10 µm.