Thermo Scientific HyClone Bovine Growth Serum, U.S. Origin is supplemented with chemically defined components including amino acids, trace metals, vitamins, and other small molecules. Save money while ensuring excellent culture results with this cost-effective alternative to FBS. Thermo Scientific Bovine Growth Serum was developed for cell culturists who are concerned about the availability of fetal bovine serum and are seeking an affordable and viable alternative. BGS* starts with Defined Bovine Calf Serum and is supplemented to stimulate cell growth and proliferation.