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Table 1 Specific yield, plasmid copy number, and repA expression in cultures of DH5α[pDMB02-GFP] with and without a temperature shift

From: Development of new plasmid DNA vaccine vectors with R1-based replicons

Temperature Time (hr)a Specific Yield (mg pDNA/g DCW) Plasmid copies/chromosome repA expressionc repA expression/plasmidd
30°C 0 NDb 42 ± 2 1.07 ± 0.10 1.07 ± 0.16
  2 1.5 ± 0.1 90 ± 9 0.69 ± 0.02 0.32 ± 0.05
  4 4.4 ± 0.2 144 ± 3 0.77 ± 0.25 0.22 ± 0.08
  8 7.0 ± 0.3 212 ± 72 1.40 ± 1.74 0.27 ± 0.36
42°C 2 2.2 ± 0.0 153 ± 3 12.50 ± 2.55 3.40 ± 0.78
  4 4.2 ± 0.1 105 ± 39 28.15 ± 1.48 11.21 ± 4.33
  8 5.1 ± 0.6 177 ± 29 24.60 ± 0.14 5.78 ± 1.12
  1. Error bars represent the standard deviation of duplicate samples.
  2. aTime after temperature shift.
  3. bNot detected (below detection limit of HPLC assay).
  4. cNormalized to repA expression at t = 0 in flask replicate 1.
  5. drepA expression multiplied by a factor of (t = 0 plasmid copy number)/(plasmid copy number of sample) to give an estimate of normalized repA expression per plasmid.