Table 2.

Median mutation frequencies in bacteria

Experiment no.	Strain BW528	No. of cultures	Median RifR mutation Frequency, × 108	Fold increase*	Fold increase* in 3MeA DNA glycosylase activity†
1	+pBAD24	26	1.5	1	1
	+p24Tag	19	1.4	0.9	12.7  ±  3.7
	+p24MAG	29	133	89	6.7  ±  1.6
2	+pBAD24	15	13.2	1
	+p24Tag	15	14.0	1.1
	+p24MAG	15	618	47
3	+pBAD24	30	0.7	1
	+p24Tag	30	0.3	0.4
	+p24MAG	30	333	476

^*Relative to pBAD24 control. 

^†Determined from similar cultures as described in Materials and Methods (mean ± SD, n = 3).