Fetal bovine serum (FBS) is a ubiquitously used essential supplement in cell culture media. FBS is a cocktail of proteins, vitamins, carbohydrates, lipids, hormones, growth factors, minerals and trace elements and is used as an universal growth supplement effective for most types of human and animal (including insect) cells. The major functions of serum in culture media are to provide: i. Hormonal factors stimulating cell growth and proliferation and promoting differentiated functions. ii. Transport proteins carrying hormones (e.g. transcortin), minerals and trace elements (e.g. transferrin) and lipids (e.g. lipoproteins) iii. Attachment and spreading factors, acting as germination points for cell attachment. iv. Stabilizing and detoxifying factors needed to maintain pH or to inhibit proteases either directly, such as αantitrypsin or α2-macroglobulin, or indirectly, by acting as an unspecific sink for proteases and other (toxic) molecules. RM10434 is fetal bovine serum collected from approved abattoirs in USA. US Origin FBS is considered the world’s standard for quality and is one of the most widely used serum in the world.