FIG. 4.

Reproducibility of the measured RJP. (A) Nine transfections of p6131-SJΔ were conducted and screened. The top four transfections were performed 4 years earlier than the bottom five. These numbers correspond to the pooled data reported in Fig. 3. (B) Ten transfections of p6131-CJΔ cointroduced with the site 2 control plasmid were analyzed. Colonies selected on chloramphenicol were typed to determine the number of site 1 and site 2 recombinants as usual (columns A and B). Colonies isolated on ampicillin after DpnI digestion of the harvested DNA were typed to determine the numbers of each parental plasmid successfully transfected as described in Materials and Methods (columns C and D). Colony counts were normalized as shown (two subsequent columns) to give the RJP (rightmost column).