Figure 1

Optimization of lactose concentration for induction in control conditions. Coomassie stained SDS-PAGE profile of the total protein extract from cell cultured in LB and induction with either IPTG or lactose with different post-induction times. 5 μg of soluble protein extract were loaded in each lane. Lane 1 no induction; 2 0.4 mM IPTG, 3 h post-induction; 3 0.4 mM IPTG, 20 h post-induction; 4 1 mM lactose, 3 h post-induction; 5 1 mM lactose, 20 h post-induction; 6 5 mM lactose, 3 h post-induction; 7 5 mM lactose, 20 h post-induction.