Plasmid Construction
Biortus routinely searches for the best expression conditions for a novel recombinant protein from the three major expression hosts (E. coli, Insect and mammalian), unless specified by clients or well-documented in literature. We offer a selection of plasmids and cells for achieving optimal expression. Here is an outline of parameters that we could try for optimal expression in E.coli:
1. Screening of Expression Tags and Plasmids
N-terminal Tags |
C-terminal Tag |
Plasmids |
2. Screening of Expression Cell Strains
BL21 (DE3) Rosetta (DE3) Origami 2 (DE3) C41 (DE3)orC43 (DE3) Arctic (DE3) Tuner(DE3)0.1mM IPTG BL21 (DE3) pLysS |
most used rare codon -S-S-& rare codon hydrophobic protein TPN30 & TPN60 chaperone lower expression for better folding lower basal expression for toxic proteins |
3. Screening with Chaperones
pG-KJE8,pGro7, pKJE7, pGTf2,pTf16
Dsba and/or Dsbc (expressed in periplasmic space with pET21a)