In vitro stability of pBP10 in M. smegmatis and Mtb in the absence of antibiotic selection. (a) Total number of M. smegmatis -pBP10, accounting for serial dilutions to show ongoing culture expansion. (b) Frequency of M. smegmatis -pBP10 plasmid-containing bacteria. (c) Frequency of plasmid carriage in M. smegmatis -pBP10 for log-phase cultures versus generations (calculated as (log(OD600t / OD600(t − 1)) / log(2)). (d) Total number of M. tuberculosis -pBP10. (e) Frequency of M. tuberculosis -pBP10 plasmid-containing bacteria. (f) Frequency of plasmid carriage in M. tuberculosis -pBP10 for log-phase cultures versus generations. Data (means ± s.d.) are shown for log-phase cultures in 7H9, 1:1 7H9 to water, 1:3 7H9 to water, 7H9 without shaking and 7H9 in 2% O2. Representative data are shown for two to five experiments performed in triplicate, except for the 2% O2 experiment, which was performed once.