Learn how to use this product Insulin-Transferrin-Selenium (ITS) is a chemically defined supplement suitable for various cell culture applications. Most commonly, ITS Solution is used as a supplement for basal cell culture media. The ITS supplement contains components required for the optimal performance of serum-free media. The supplementation of ITS to conventional nutrient media reduces the FBS requirements for routine cultivation of many cell lines. ITS is provided as a 100x concentrate.