Expression Services
The facility currently utilizes E. coli and mammalian cell expression systems. Typically, users provide a sequence-verified expression vector containing the gene(s) of interest. Alternatively, our staff can undertake expression vector construction if requested.
E. coli Expression
- Small-scale test expressions can be conducted to determine optimal expression conditions.
- Large multi-liter shaking, suspension cultures of E. coli can be grown and processed at temperatures ranging from 18掳C to 42掳C. Max capacity is 18L at a time.
- The facility stocks a variety of E. coli strains to address specific issues like rare-codon usage, protein misfolding, and expression in specialized media, for example, for the production of selenomethionine variants or 13C and 15N labeling.
Mammalian Cell Expression
- Our go-to cell lines are Expi293 (HEK293) and ExpiCHO (CHO-S). Both are mammalian cell lines selected for high protein expression and dense cell growth, and both are adapted for suspension culture.
- We can culture other suspension or adherent cell lines if special circumstances are required, such as limiting glycosylation or enabling DHFR stable cell selection.
- Small-scale test expressions can be performed with virtually any suspension or adherent culture. Typically these are done for a simple ‘yes/no’ answer to the question of whether a protein expresses, but they can be adapted for very small scale preps.
- For large scale expression experiments in suspension culture, we have a maximum of ~15L capacity.