ExpiCHO™ Expression Medium is a GMP-manufactured, chemically-defined, serum-free, protein-free, animal origin–free medium specifically designed for high-density growth and transfection of suspension-adapted Chinese hamster ovary (CHO) cells. It is a core component of the ExpiCHO™ Expression System Kit (Cat. No. A29133) for scalable transient protein production.

ExpiCHO Expression Medium:
• Supports growth of suspension CHO cultures to densities of over 2 x 10⁷ cells per mL, with >95% cell viability
• Uses a transfection-compatible, serum-free suspension culture medium that enables high transfection efficiencies of >90% with ExpiFectamine™ CHO transfection reagent
• Supports transient transfection of suspension CHO cells at a density of 6 x 10⁶ cells per mL
• Facilitates sustained, high-level expression of high-density transiently transfected cultures, achieving yields of up to 3 g per L of recombinant protein
• Supports growth and transfection of CHO cells in culture formats from <1 mL in multi-well plates to >10 L in benchtop bioreactors
• Does not contain phenol red

ExpiCHO Expression Medium is formulated with GlutaMAX™-I reagent. It is ready to use, with no supplementation required. The chemically-defined formulation results in high reproducibility and lot-to-lot reliability. For highest level transient protein expression, the medium is used in combination with a matched culture feed, ExpiCHO™ Feed, which is supplied as part of the ExpiFectamine™ CHO Transfection Kit (Cat. No. A29129). ExpiCHO Expression Medium is not recommended for adherent cell cultures. Cells are typically grown in Erlenmeyer-style flasks on a shaker platform in a humidified, CO₂ cell culture incubator. However, cultures are scalable from volumes of <1 mL in multi-well plates to >10 L in bioreactors.