Expression of Recombinant Proteins with the Expi293™ Expression System

The Gibco™ Expi293™ Expression System is a high-yield transient expression system based on suspension-adapted Human Embryonic Kidney (HEK) cells that are highly transfectable and that will grow with a doubling time of 24-25 hours during log phase growth to high density in Expi293™ Expression Medium. Each Expi293™ Expression System Kit provides sufficient cells, culture medium, and reagents to transfect 1 liter of cell culture. Transient expression is powered by the cationic lipid-based ExpiFectamine™ 293 Reagent in combination with specialized transfection enhancers. All components work in concert to generate 2- to 10-fold higher protein yields than previous generation transient expression systems such as the FreeStyle™ 293 Expression System. The major components in this expression system are described briefly below. A more detailed description is in the Expi293™ Expression System User Guide.

Expi293F™ Cells are human cells derived from the 293F cell line. They are maintained in suspension
culture and will grow to high density in Expi293™ Expression Medium. Expi293F™ Cells are highly transfectable and generate superior protein yields compared to standard 293 cell lines in transient protein expression

Expi293™ Expression Medium is a chemically defined, serum-free, protein-free medium for growth and transfection of HEK 293 cells. The Expi293™ Expression Medium is formulated with GlutaMAX™ I Supplement. The chemically defined formulation that contains no human or animal-origin components results in high reproducibility and lot-to-lot reliability. Expi293™ Expression Medium:

Supports growth of suspension Expi293F™ cultures to densities of 12–15 × 10⁶ cells/mL
Enables transfection efficiencies of >80% using ExpiFectamine™ 293 Transfection Reagent
Enables sustained, high-level expression of high-density transiently transfected cultures, achieving yields of up to 1 gram per liter of recombinant protein
Supports growth and transfection of Expi293F™ cells in culture formats of <1 mL in multi-well plates to >10 L in disposable bioreactors
Does not contain phenol red

ExpiFectamine™ 293 Reagent is designed for transfection of high-density suspension cell cultures. The ExpiFectamine™ 293 Reagent enables scaling transfections for culture volumes of less than 1 mL to greater than 10 liters, while maintaining equivalent volumetric protein yields. Matching Transfection Enhancers #1 and #2 boost transfection performance and protein expression to achieve protein yields that are 2- to 10-fold higher than other transfection reagents used on high-density 293 cell cultures.

Opti-MEM™ I Reduced Serum Medium is a serum-free medium used to complex plasmid DNA with ExpiFectamine™ 293 Reagent, providing superior protein expression through efficient transfection.

Antibody-Expressing Positive Control Vector is a positive control for transfection and expression in Expi293F™ cells. The rabbit IgG that is produced in Expi293F™ cells after transfection with the control vector is secreted into the Expi293™ Expression Medium, with optimal yields occurring 5–7 days post-transfection.

To take advantage of the Gibco™ Expi293™ Expression System technologies available through the Yale/NIDA Neuroproteomics Center please contact Dr. Pietro DeCamilli for proteins involved in phosphoinositide metabolism and Dr. Angus Nairn for all other proteins.