HEK293SF-3F6 and HEK293-6E expression platforms (L-10894 / 11266 / 11565)


There is an increasing demand for biopharmaceuticals such as vaccines, humanized monoclonal antibodies, and gene therapy products produced from animal cell culture processes. The NRC's HEK293SF-3F6 expression system enables the high yield production of viral vector and post-translationally modified recombinant proteins through suspension-growing, serum-free adapted cell lines. It provides an optimized, chemically defined formulation for serum-free suspension culture of this cell line. The cell line can be used in combination with the cumate and coumermycin switches, which enable producers to turn on the expression of a given protein only when needed.

Technology transfer

  • Non-exclusive R&D and/or commercial exploitation licence
  • R&D agreement for development of custom cell lines

Market applications

  • Transient expression of recombinant proteins and viral (adenoviral, adeno-associated viral, lentiviral, and retroviral) vectors for R&D purposes
  • Fully-scalable stable expression of recombinant proteins, viral vectors, and lead candidates for R&D and commercial purposes

How it works

HEK293SF-3F6 cell line

A stepwise approach was employed to select a serum-free adapted clone (293SF-3F6) from a suspension-growing derivative of the human embryonic kidney cell line HEK293. A preferred commercially available serum-free media was also identified.

HEK293-6E cell line

Shorter, functional forms of EBNA1 reduced the difficulty of obtaining stable clones, allowing the isolation and characterization of a new 293EBNA1 cell line, 293-6E, that stably expresses a truncated EBNA1 protein. Further enhancement of r-protein expression was achieved by co-expression of selected genes in cis or trans. Use of an expression cassette for transient co-expression of truncated forms of EBNA1 in cis or in trans increased r-protein production in 293EBNA1 and non-EBNA1 cells as well as in the new 293-6E cell line. A modified serum-free medium amended by the addition of various additives was shown to increase r-protein and viral vector production.


  • High yield, low cost protein production for research and biomanufacturing
  • Transient or stable expression
  • Family of validated pTT® vectors
  • Choice of proprietary cell lines or custom cell line development to best suit your expression needs
  • Master cell bank documentation for commercial production (293SF-3F6)
  • Two switches (cumate and coumermycin) allow you to turn on and off the expression of a given gene during production
  • Serum-free media enables easy recovery of recombinant proteins
  • Compatible with commercially available feeds; custom fed batch development
  • pTT® is a registered trademark of the National Research Council of Canada.

Please note: In the 1970s, Dr. Frank Graham developed the HEK293 cell line, which is now widely used for academic research and in the pharmaceutical and biotechnology industries around the world. The NRC has developed proprietary versions of the HEK293 cell line, referred to as HEK293SF‑3F6 and HEK293‑6E.


  • NRC file 11266 (vector/cassette): Patents granted in Canada, Europe, and Singapore; pending in the United States.
  • NRC file 10894 (HEK 293SF-3F6 cell line): Patents granted in Canada and the United States.
  • NRC file 11565 (HEK 293-6E cell line): Patents granted in the United States; pending in Canada, Europe, and Singapore.
  • NRC file 11225/11648 (Cumate switch): Patents granted in Canada, the United States, and Europe.
  • NRC file 11444 (Coumermycin switch): Patents granted in Canada, the United States, Europe, Australia, New Zealand, and Japan.

Related links

Contact us

Email: CNRC.PlateformesCellulaires-CellPlatforms.NRC@cnrc-nrc.gc.ca