Fetal Bovine Serum Advanced (FBS Advanced), Heat Inactivated has reduced batch-to-batch variations compared to standard FBS. The heat inactivation process inactivates the complement system, antibodies, and other active enzymes. Serum is the blood component obtained after coagulation and removal of cellular components. Besides serum proteins it contains, e.g., growth factors, amino acids, and hormones. This comprehensive mix makes serum one of the most important supplements for supporting cell growth and proliferation for in vitro cell culture. Of special interest is fetal bovine serum (FBS). It is especially rich in growth factors and low in antibodies, which may influence the cell culture work. Raw fetal bovine serum is a natural byproduct of the meat and dairy industry. It is obtained from bovine blood showing significant batch variations due to various environmental influences, e.g., nutrition or health state of animals. Batch-to-batch variations of fetal bovine serum can have major impacts on the reproducibility of scientific results. Capricorn Scientific’s sophisticated treatment process during pooling and filtering significantly reduces batch-to-batch variation in FBS Advanced. Usually, once successfully tested on a cell line, no further batch testing is necessary. As mentioned above, heat inactivation will inactivate the complement system, antibodies, and other active enzymes. It has to be done in a carefully controlled process to avoid damaging the cell growth-promoting properties of the serum and reducing the formation of unwanted precipitates. The process involves heating the serum in a shaking water bath at exactly +56 °C for 30 minutes. The shaking will help avoid the formation of protein and other forms of precipitates. After 30 minutes the serum is then cooled back down to room temperature as quickly as possible to avoid excessive exposure to heat, which can damage, e.g., growth factors and vitamins.