Apo-Transferrin (ATF) is sourced from FDA approved plasma and has been tested and found negative for antibodies to many common human blood viruses. ATF plays a physiological role in the transportation and distribution of iron amongst bodily organs. Apo-Transferrin is also an important component used for the cultivation of mammalian cells in-vitro because it acts as a transport factor for defined culture media. This property is crucial for long-term mammalian cell growth in-vitro since ATF operates as a detoxificant in media by binding to contaminating metal ions. Some other common uses for Apo-Transferrin are affinity purification and receptor mediated transfection of DNA-like molecules into cells.