The *E. coli* expression system is widely regarded as the most common and cost-effective classic expression system, thanks to its simple structure, well-defined genetic background, high target gene expression levels, and short cultivation cycles. Over the past few decades, this system has undergone continuous development and refinement, making it a staple for both academic research and industrial applications in the production of various recombinant proteins. It is primarily used for the preparation of antigens and ligands, as well as the expression of cytokines and proteins derived from bacteria (such as *Staphylococcus aureus* and *E. coli*).

UpingBio possesses extensive experience in *E. coli*-based protein expression and purification; by continuously optimizing experimental conditions, we are able to resolve complex challenges encountered during these processes.

Backed by extensive expertise and technical proficiency, we resolve difficult issues in protein expression and purification through continuous process optimization. Over the past 15 years—since 2007—we have successfully developed more than 7,000 types of recombinant proteins expressed in *E. coli*, including hundreds of high-purity, biologically active proteins.

Well-defined genetic background;

Short protein expression cycle and ease of scale-up;

Rapid growth rate and high expression levels;

Wide range of vectors and fusion tags available;

Parameters can be adjusted to achieve optimal expression.

Exceptional cost-effectiveness, with prices starting as low as 3,500 RMB;

Expression success rate of up to 98%;

Supernatant recovery rate >72%;

Short turnaround time, with delivery within 25 working days;

Yield of up to 200 mg/L.

Risk-free custom service: no charge unless successful.

Note: This risk-free custom protein service applies only to proteins of 800 amino acids or fewer. If you require the expression of a protein exceeding 800 amino acids, we will charge on a step-by-step basis.