Fig. 5

Screening the production of membrane proteins in BL21(DE3), C41(DE3) and C43(DE3). The production of a set of membrane protein GFP-fusions (Additional file 1: Table S1) was assessed in BL21(DE3) cells cultured in the presence and absence of IPTG, and C41(DE3) and C43(DE3) cells cultured in the presence of IPTG. For BL21(DE3)-based cultures membrane protein-GFP production was monitored by measuring GFP fluorescence per ml of culture 4 and 24 h after the addition of IPTG (relative fluorescence unit, RFU). For C41(DE3) and C43(DE3)-based cultures fluorescence per ml of culture was monitored 24 h after the addition of IPTG. RFUs/ml per A₆₀₀ are shown in Additional file 1: Figure S1. Notably, not adding IPTG to C41(DE3) and C43(DE3) cultures leads to lower production levels than adding IPTG (see Additional file 1: Figure S2)