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

Table 2 Specific yield, plasmid copy number, and repA expression from cultures of DH5α[pDMB-ATG] 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	13 ± 3	0.09 ± 0.01	0.30 ± 0.09
	2	0.2 ± 0.1	20 ± 4	0.06 ± 0.00	0.13 ± 0.03
	4	1.0 ± 0.0	54 ± 1	0.20 ± 0.02	0.15 ± 0.02
	8	2.3 ± 0.3	96 ± 27	0.32 ± 0.02	0.14 ± 0.04
42°C	2	1.9 ± 0.1	243 ± 32	1.00 ± 0.08	0.17 ± 0.03
	4	5.1 ± 1.9	407 ± 210	15.20 ± 1.13	1.56 ± 0.83
	8	11.4 ± 1.7	476 ± 176	9.85 ± 0.64	0.86 ± 0.34

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 from pDMB02-GFP at t = 0 in flask replicate 1 (Table 1).
^drepA expression multiplied by a factor of (t = 0 pDMB02-GFP copy number)/(plasmid copy number of sample) to give an estimate of relative repA expression per plasmid.

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