Fig. 6. Cells transfected with EGFP-UBF but not deletion mutants show retarded incorporation of rhodamine-labelled dUTP in an in situ replication assay. Cells were infected with adenovirus and simultaneously transfected with various plasmids as indicated. After 18 hours the cells were assayed for incorporation of Rho-dUTP as outlined in the Materials and Methods. In each panel the fusion protein is in green and the labelled DNA is in red. (A) Two cells infected with adenovirus expressing different amounts of EGFP-UBF and labelled with Rho-dUTP. (B) The same cells, but with the sensitivity of the photodetectors raised to reveal the faint labelling. (C) A group of infected cells, some of which are expressing the deletion mutant UBF1-192EGFP, but with the microscope laser power and photo detector settings the same as in A for comparison. All images are of a single focal plane approximately 0.3 µm depth; bar, 10 µm.