Fetal bovine serum
（重定向自Fetal calf serum）
Fetal bovine serum (FBS) or fetal calf serum (spelled foetal in Commonwealth English) is the blood fraction remaining after the natural coagulation of blood, followed by centrifugation to remove any remaining red blood cells. Fetal bovine serum comes from the blood drawn from a bovine fetus via a closed system of collection at the slaughterhouse. Fetal bovine serum is the most widely used serum-supplement for the in vitro cell culture of eukaryotic cells. This is due to it having a very low level of antibodies and containing more growth factors, allowing for versatility in many different cell culture applications.