Bacterial Expression System | Protein Services

The advantages of E. coli expression systems include low cost, high expression, ease of scale up, and short turnaround time. Our collection of more than 10 host strains and numerous expression vectors guarantees selection of the most efficient expression system. To increase protein solubility, expression levels, and ease of purification, multiple fusion/affinity tags are available. Our proprietary AIE technology allows high yields of toxic proteins. For insoluble proteins we have developed an effective protein refolding system consisting of 20 refolding buffers optimized with 9 parameters. If large amounts of protein are required, we can produce and purify from cultures as large as 35-500 liters. Metabolic labeling with stable isotopes is also offered in the E. coli system.

Phase I: Gene Synthesis and Subcloning

We can take a customer provided cDNA or optimize and synthesize any desired coding sequence and subclone it into a large variety of prokaryotic expression vectors. Once cloned, all constructs are sequence verified.

Phase II: Pilot Protein Expression and Purification

Expression constructs can be transfected into any of a variety of E. coli strains and clones screened in small-scale pilot experiments to determine the best induction and expression conditions. Once expression conditions are optimized, we do a pilot scale purification to identify the most efficient purification procedure.

Phase III: Protein Expression and Purification

We use our optimized conditions to scale up expression to one liter cultures. We access multiple purification strategies to isolate several milligrams of product at this stage. If larger quantities are required, we can scale up to 35-500L culture sizes.