ITS-B Supplement 100X, Liquid w/ 1 mg per ml Insulin from bovine pancreas, 0.55 mg per ml Human Transferrin, 0.5 µg per ml Sodium Selenite and 50 mg per ml Bovine serum albumin in Earle’s Balanced Salt Solution w/o Phenol red

ITS-B supplement is a basal growth factor supplement used to reduce the serum requirements in reduced serum and serum free cell culture systems. Insulin is a peptide hormone responsible for uptake, utilization and storage of glucose by cells. Insulin is often used as a medium supplement for cell culture in the range of 1-10 µg/ml depending upon the cell type. Transferrin is a glycoprotein responsible for delivery of iron to cells. Most of the stimulatory activity of transferrin is attributed to its own iron binding properties. Transferrin has a stimulatory effect on many cell types and is used in cell culture at a concentration of 1-10 µg/ ml. Selenium is an essential trace element required for normal cell growth and development. Bovine serum albumin is a common supplement used in cell culture. It serves several functions such as a detoxifying agent, stabilizing buffer and as a transport protein. It is generally used in cell culture at a concentration of 0.1 to 1gm per litre.