Figure 2. Procedure for maintenance experiments. Duplicate tissue culture dishes (1 and 2) were processed 30 min (G0) and 96 h (G1) postransfection, respectively. The dish 3 was used for subsequent cell generations (G2-G5). The dish 4 was maintained until the end of the assays. At each time point the DNA was extracted and assayed as described in each figure legend.