The HEK 293 cell line was developed by Dr. Graham in the 1970s (1). This cell line, human embryo kidney cells transformed by the E1 region of human Adenovirus type 5, has a number of properties that make it uniquely valuable for research in virology, cell and molecular biology as well as in numerous pharmaceutical applications. The original paper describing the generation of 293 cells has been cited over 7000 times since its publication in 1977. The cells are excellent hosts for a number of adenoviruses that cannot be propagated in other cells, they produce a number of transcription factors and other products, and they can be readily transformed by DNA to potentially generate an infinite number of derivative cell lines expressing commercially useful proteins.  The 293 cell line has been extensively characterized in Dr. Graham’s lab by Southern blot hybridization and DNA sequencing (2), among other analyses. Based on their unique characteristics and on genetic analysis including DNA sequencing, Dr. Graham’s 293 cells are an easily identifiable biological material and all 293 derivative cells can be readily traced to the original parental 293 cell line. Although Dr. Graham never sought patent protection on his unique cell line, he has exerted his rights to the cells, and their DNA, by limiting their use to non-commercial research purposes unless the user has a license.

Over the years, Dr. Graham has provided his 293 cells to numerous individuals under the condition that they be used for non-commercial purposes. Although 293 cells are available from a number of sources, including a few commercial suppliers, only DMKS Research (email: DMKS_Ltd@shaw.ca) has been designated by Dr. Graham as the exclusive authorized supplier of low passage 293 cells, and only DMKS can trace their history back to the original transformation.

DMKS 293 cells are low passage, usually 26-28, measured directly from the initial 1973 isolation, and have been cultured only under Graham lab conditions that maintain the desirable characteristics of the original cells: namely high transfection efficiencies, excellent monolayer properties under agar overlay for adenovirus plaque production, good adenovirus vector yields.

Also available from DMKS are 293N3S cells adapted to growth in suspension (3).

DMKS 293 cells are tested for viability, certified to be mycoplasma-free, and are guaranteed to be healthy if our scale up procedure is followed. The DMKS low passage 293 cells have been exposed to fetal bovine serum and horse serum but no other products, such as trypsin, derived from animals.

These advantages should be attractive to researchers who cannot afford to trust their experiments to poorly characterized 293 cells or who, from ethical considerations, do not wish to obtain materials from unauthorized suppliers.