CHOgro® High Yield Expression System

The most advanced system for transient transfection and protein production in suspension CHO cells

A New and Improved Transient Expression System for CHO Cells

The CHOgro® High Yield Expression System Features CHOgro® Titer Enhancer. The CHOgro® High Yield Expression System (MIR 6270) includes the same components of the first-generation CHOgro® Expression System (MIR 6260) and features a new component – the CHOgro® Titer Enhancer [which is also included in the CHOgro® Transfection and Titer Enhancer Kit (MIR 6225)]. Adding the CHOgro® Titer Enhancer and shifting the cell culture temperature to 32°C yields a significantly higher increase in in titers over the original CHOgro® Expression System.

CHOgro® High Yield Expression System Protocol

CHOgro® High Yield Expression System Streamlined Workflow. The CHOgro® High Yield Expression System was engineered to maximize transient protein production in suspension CHO cells, while still maintaining a simple and cost-effective workflow. The ability to add expression enhancers at the time of transfection and immediately shift cell cultures to hypothermic conditions provides researchers with more flexibility in the timing of their experiments while reducing the risk of contamination caused by repeated handling of the culture.

Obtain Higher Protein Titers

CHOgro® High Yield Expression System Results in Higher Protein Titers. The CHOgro® High Yield Expression System (MIR 6270) and the CHOgro® Expression System (MIR 6260) were compared for human IgG1 antibody production. Antibody was produced by transient transfection using the TransIT-PRO® Transfection Reagent (Mirus Bio) at a 1:1 reagent-to-DNA ratio (vol:wt) and 1 µg plasmid DNA per milliliter of culture. FreeStyle™ CHO-S cells (ThermoFisher Scientific) were cultured in CHOgro® Expression Medium (Mirus Bio) and plated at a density of 2 or 4 x 10⁶ cells/ml in non-treated 6-well plates (2ml/well) for transfection. As indicated, the CHOgro® High Yield culture was shifted to 32°C immediately post-addition of the transfection complexes to the culture. Day 10 supernatants were analyzed using a standard sandwich human IgG ELISA. Error bars represent the standard deviation of triplicate technical replicates.

The CHOgro® High Yield Expression System Outperforms the ExpiCHO Expression System Using Multiple Antibody Constructs. Six different IgG1 antibody constructs, including five therapeutically relevant constructs synthesized in the same vector backbone were produced by transient transfection using either the TransIT-PRO® Transfection Reagent (Mirus Bio) at a 1:1 reagent-to-DNA ratio (vol:wt) and 1 µg plasmid DNA per milliliter of culture in FreeStyle™ CHO-S cells (ThermoFisher Scientific) cultured in CHOgro® Expression Medium (Mirus Bio) at a cell density of 4 x 10⁶ cells/ml, or the Expifectamine CHO Transfection Kit (ThermoFisher Scientific) at a 3.2:1 reagent-to-DNA (vol:wt) and 1 µg plasmid DNA per milliliter of culture in ExpiCHO-S cells (ThermoFisher Scientific) cultured in ExpiCHO Expression Medium (ThermoFisher Scientific) at a cell density of 6 x 10⁶ cells/ml. All cells were split into 125 ml Optimum Growth flask (25 ml/flask, Thomson Instrument Company) at the time of transfection. The CHOgro® Titer Enhancer was added immediately post-addition of transfection complexes and the culture was incubated at 32°C shaking until harvest for the CHOgro® High Yield Expression System. The Max titer protocol was followed for the ExpiCHO Expression System (ThermoFisher Scientific): Expifectamine CHO Enhancer and Feed (ThermoFisher Scientific) were added at 24 hours post-transfection and cultures were shifted to 32°C. At Day 5 a second volume of the ExpiCHO Feed (ThermoFisher Scientific) was added to the flask. Day 7 and 14 supernatants were analyzed using a standard sandwich human IgG ELISA. Error bars represent the standard deviation of triplicate technical replicates.