Mammalian cell culture in a serum free medium requires an iron transporter such as transferrin. The transferrin iron content can be adjusted to give near 100% saturation - holo-transferrin or depleted to give near zero iron bound - apo-transferrin. Siderotransferrin has iron levels between. For tissue culture media, human cells grow better in cell culture media made with human rather than bovine serum components. Scipac offer both Pasteurised and non-Pasteurised (more economical) versions of Apo Transferrin.