Serum plays a pivotal role in cell culture as a complex mixture of proteins, growth factors, hormones, and nutrients essential for supporting cell growth and viability outside the body. Derived from various animal sources such as fetal bovine, newborn calf, and human blood, serum provides a rich environment that mimics physiological conditions necessary for cells to proliferate and maintain their specialized functions. Researchers rely on serum to optimize cell culture conditions, ensuring reliable experimental outcomes in biomedical research, pharmaceutical development, and biotechnology applications.