Savage (2007) targetted 120 E. coli membrane proteins for in vivo and in vitro expression.
These 36 MemProtEx-VivoWeak proteins were expressed weakly in vivo ( < 2 mg/L).
Savage et al. (2007) testing expression of 117 N-terminal His-tagged clones in vivo using a pET3-derived vector in BL21(DE3) cells.
In vivo expression, and in vitro expression using S30 extracts, were assessed as negative, weak positive, or strong postive using Western blots.