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

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

Temperature	Time (hr)^a	Specific Yield (mg pDNA/g DCW)	Plasmid copies/chromosome	repA expression^c	repA expression/plasmid^d
30°C	0	ND^b	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

Error bars represent the standard deviation of duplicate samples.
^aTime after temperature shift.
^bNot detected (below detection limit of HPLC assay).
^cNormalized to repA expression at t = 0 in flask replicate 1.
^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.

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