Gibco® Insulin-Transferrin-Selenium (ITS-G) is used as a basal medium supplement in order to reduce the amount of fetal bovine serum (FBS) needed to culture cells. Originally used with RPMI 1640 and Minimum Essential Medium (MEM), ITS-G solution is now routinely used with other basal media to support a wide variety of cell types in the presence of 2–4% FBS.
Insulin promotes glucose and amino acid uptake, lipogenesis, intracellular transport, and the synthesis of proteins and nucleic acids. Transferrin is an iron carrier and it may also help to reduce toxic levels of oxygen radicals and peroxide. Selenium, as sodium selenite, is a co-factor for glutathione peroxidase and other proteins, and is used as an anti-oxidant in media.