I ran out of OptiPRO SFM. Can I use use Opti-MEM I Reduced Serum Medium to make my DNA-ExpiFectamine 293 transfection complexes?
We do not recommend using OptiPRO SFM to make DNA-ExpiFectamine 293 transfection complexes. If you require an animal origin-free system, you may use FreeStyle 293 Expression Medium to make the complexes, but keep in mind that there will be a 10-20% drop in final protein yields.
Can FreeStyle 293-F cells grown in FreeStyle 293 expression medium be transfected with ExpiFectamine293 Reagent along with enhancers? Is so, will the transfection efficiency be higher than that with FreeStyle Max Reagent?
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.
How many days should I wait before harvesting my protein in the Expi293 Expression System?
The optimal expression time will be different for each protein, but most tested proteins fall within a 3-7 day window. As the system scales well, it is recommended you run a small-scale pilot experiment to determine when to harvest your protein of interest prior to scaling up.