Insulin-Transferrin-Selenium-Ethanolamine (ITS -X) Supplement is used as a basal medium supplement in order to reduce the amount of Fetal Bovine Serum (FBS) needed for regular maintenance and low density adherent culturing of cells. It is formulated with Earle's Balanced Salt Solution. BasalMedia provides 3 types of ITS, which are commonly used ITS-G; ITS-A, which is used for adherent cell culturing; and ITS-X, which is used in complex media containing sodium pyruvate(e.g. F-12 Media or DMEM/F-12 Media). 2%¡«4% FBS should be added to the medium at the initial stage of culturing, the amount can be further decreased after cells adapt.