South American serum, often referred to as South American Fetal Bovine Serum (FBS), is a type of fetal bovine serum sourced from cattle in South American countries such as Brazil or Argentina. It is widely used in cell culture as a supplement that provides essential growth factors, proteins, and nutrients to support cell growth and proliferation. South American serum is often preferred because of its lower risk of contamination with certain viruses and pathogens compared to serum from other regions.