Fetal Bovine Serum Advanced (FBS Advanced) has reduced batch-to-batch variations compared to standard FBS. 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.