FreeStyle™ 293-F Cells - FAQs

Other 293 cell lines may be used with the FreeStyle 293 Expression System. However, they would have to be adapted to serum-free suspension culture in FreeStyle 293 Expression Medium and evaluated for transfection and expression.

When comparing FreeStyle 293-F cells with FreeStyle CHO-S cells for average range of antibody and protein yield, it is definitely expected that antibody yield will be higher in FreeStyle 293-F cells than in FreeStyle CHO-S cells, when generated by transient transfection. On the other hand, antibody yields in stable CHO cells can be much higher. For non-antibody proteins, it is impossible to predict which of the two cell lines may provide higher yields.

You should be able to use the ExpiFectamine293 Reagent for transfection of Freestyle 293-F cells grown in FreeStyle 293 Expression Medium; however, the enhancers will provide only a little boost in expression as they are designed to work with higher density cultures that FreeStyle 293 Expression Medium cannot support.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

We typically keep the culture going for 7-10 days posttransfection. After that, protein expression may drop.

Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.

Our recommendation of 8% CO2 for the optimal growth of Freestyle 293 cells in Freestyle 293 Expression Medium is based on the bicarbonate content in the media and growth conditions of the cells observed by R&D. That said, you may use lower concentrations of CO2 if necessary (5% is common) to grow these cells. You may observe slightly slower growth kinetics or lower cell concentrations, but functionally the entire system will still work.

The CO2 requirement is dependent on the media. Our serum-free 293 media require 8% CO2 to best buffer the media.

Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.

FreeStyle 293-F cells are derived from HEK293 cells; they were just cloned extensively for growth, viability, and protein production in the new serum-free FreeStyle 293 medium. Thermo Fisher Scientific coined the name “FreeStyle” to signifiy the freedom of switching the cells to the defined serum-free FreeStyle media system.

The parental HEK293 cells, if adapted to the same media as FreeStyle 293F cells, should have the same transfection efficiency. However the final protein production levels may be very different as the FreeStyle 293F cells have been cloned and selected for maximal protein production.

Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.