Fetal bovine serum is one of the secondary derivatives of dairy production. It is extracted from the blood of a bovine fetus pressed out in a slaughterhouse via a standardized antiseptic procedure. It comes in the form of a sterilized brown fluid obtained when fetal animal blood is left to naturally coagulate and then is subjected to centrifugation to rid it of all residual red blood cells. FBS  is immensely rich in growth stimulants such as nutrients, amino acids, proteins and sugars. In addition, it has significantly low levels of antibodies which are potential inhibitors of general cell growth, hence it is an ideal component for a wide range of cell culture operations.

Given that fetal bovine serum has an abundant availability of growth-stimulating substances for embryos, this sterile liquid has been put to use in unparalleled ways in cell culture media. When a cell is cultured in a medium replete with a wide array of proteins and other growth factors, it experiences a vitalizing lease of life that helps it survive, thrive and multiply. An appropriate concentration of fetal bovine serum in a medium provides a proportionate supply of propitious substances that promote some crucial metabolic functions of a cultured cell.