As an expert in protein expression, Creative BioMart is deeply aware of the influence of the selection of the expression system on the quality and yield of final protein products. Our E. coli heterologous protein expression platform can provide a variety of promoter system expression services according to customer requirements. The overview of these expression systems is listed below for customers to choose according to their own needs. of course, if you have difficulty deciding the most appropriate system, we are here to provide technical advice. Just make an inquire online or contact us.
| PROMOTERS | EXPRESSION LEVEL | INDUCTOR | PATHWAY FEATURES |
| Lac promoter | Low level up to middle | IPTG | A. Weak, regulated suitable for gene products at the very low intracellular level. B. Comparatively expensive induction. |
| Trc and Tac promoter | Moderately high | IPTG | A. High-level, but lower than T7 system. Regulated expression is still possible. B. Comparatively expensive induction. High basal level. |
| T7 RNA polymerase | Very high | IPTG | A. Utilizes T7 RNA polymerase. High-level inducible overexpression B. T7lac system for tight control of induction needed for more toxic clones. C. Quite expensive induction. Basal level depends on strain used (pLys). |
| Phage promoter pL | Moderately high | Temperature shift | A. Temperature-sensitive host required. B. Less likelihood of "leaky" un-induced expression. Basal level; high basal level by temperatures below 30°C. No inducer. |
| tetA promoter/operator | Variable from middle to high level | Anhydrotetracyclin | A. Tight regulation. Independent of metabolic state. Independent of E. coli strain. B. Relatively inexpensive inducer. Low basal level. |
| PPBAD promoter | Variable from low to high level | L-arabinose | A. Can fine-tune expression levels in a dose-dependent manner. B. Tight regulation possible. Low basal level. Inexpensive inducer. |
| PBAD promoter | Variable from low to high level | — | A. Tight regulation. B. Low basal activity. Relatively expensive inducer. |
