Does anyone have experience of the pCEP4 vector from Invitrogen? It has both EBNA and OriP on the vector. We have a user who already has their gene of interest in this vector and we would like to make a serum-free transfection production of the protein. Does anyone know whether the HEK293 cells to be used also need to have the EBNA gene or if other regular HEK293 cells could also be used? If EBNA-cells are needed, is there anyone who can share suspension growing HEK293-EBNA cells?
I would be grateful for advice!
pCEP4 contains both EBNA1 gene and corresponding OriP origin of replication thus enabling episomal replication in any 293 cell line. But still, as shown in direct comparison in Durocher et al. (2002), Nucleic Acids Res 30(2):e9, Figure 2B, you may obtain higher yields using 293E cell line. But I suggest that you use whatever 293 cell line you have at hand and if the yield is sufficient, there is no need to fetch 293E cell line.
We decided to do just that, and try our regular 293 cells first to see if we get enough protein. If not, we could turn to the cells with EBNA (preferably suspension cells, if they would be available to us).