Evaluation of recombinant human transferrin (DeltaFerrinTM) as an iron chelator in serum-free media for mammalian cell culture

DeltaFerrin^TM, a yeast-derived recombinant human transferrin produced by Delta Biotechnology Ltd. (Nottingham UK), was found to be a suitable replacement for holo human transferrin in serum-free culture media of the MDCK cell line (chosen because of its transferrin dependence) in short-term screening assays. Long-term subculture was achieved with DeltaFerrin^TM supporting growth equivalent to that of holo human transferrin. DeltaFerrin^TM and a selection of chemical iron chelators were found in short-term assays to be equivalent to holo human transferrin in supporting growth of MDCK, BHK-21-PPI-C16 and Vero-PPI. In long-term subcultures, however, only DeltaFerrin^TM was found to support cell growth in a manner essentially equivalent to holo human transferrin in all three cell lines. For both BHK and Vero variants tested, recombinant preproinsulin production was unaltered by replacing holo human transferrin with DeltaFerrin^TM. As such, this is the first report of a recombinant human transferrin produced under animal-free conditions that can act as a universal iron chelator for cells grown in serum-free media (SFM).