Why is blood serum used in Animal Cell Culture?

Not only does it provide nutrients, but serum also has growth factors, hormones, carrier proteins, and macromolecules. A lot of researchers now use serum-free medium like DMEM for ethical and contamination reasons.

While serum is mostly used for cell culture, it is also used in other lab techniques, such as western blotting and flow cytometry as it is rich in proteins and can help minimize the non specific binding of antibodies.

Serum is a very complex supplement containing mostly proteins but also growth factors, hormones, amino acids, sugars, trypsin inhibitors, and lipids. The most common types of sera include fetal bovine (FBS), newborn calf (NCS), horse (equine), pig (porcine), and human. FBS has been adopted as the standard supplement because of its rich content of growth factors and its low gamma globulin content.

For many cell types, DMEM is not enough to sustain survival and duplication of cells, so most DMEM are supplemented by 5-10% FBS or FCS (Fetal Calf Serum).