Additional file 1 of T7-lac promoter vectors spontaneous derepression caused by plant-derived growth media may lead to serious expression problems: a systematic evaluation

Additional file 1: Expression leakage of GFPuv in E. coli BL21(DE3) [pET21d(+)-gfpuv] cells grown in media containing selected peptones. The cultivation, sample preparation and analysis were identical to that described in Fig. 2, except that a different peptone was supplemented in the composition of the medium instead of the most commonly used soya peptone and tryptone peptone: A wheat extract; B tryptose peptone; C gelatin peptone; D casein peptone; E proteose peptone; and F peptobak.