Fetal Bovine Serum (FBS)
Serum containing growth factors is usually prepared from the blood of calves or fetal calves and is added to cell medium to induce cell proliferation. In response to a wounded tissue, blood clots form to attenuate further bleeding. Blood clots form due to adherence of blood platelets which form a matrix that contracts to trap most of the cellular components of the plasma (ex. red and white blood cells). The clear fluid remaining after clot formation and retraction is the serum.
Blood platelets store growth factors (i.e. mitogens) in secretory (exocytotic) vesicles called α-granules. As platelets aggregate to form the blood clot matrix, the α-granules fuse with the plasma membrane to release (i.e. secrete) growth factors to attract fibroblasts to the wound site and stimulate their proliferation. The growth factors serve as ligands that bind complimentary cell-surface receptors on the fibroblasts. Examples of such growth factors include platelet-derived growth factor (PDGF), and epidermal growth factor (EGF). Unlike the cellular components of blood, growth factors secreted by platelets are contained within the serum, and are responsible for promoting proliferation when supplemented into cell culture media. In addition to growth factors, the globular protein, bovine serum albumin (BSA), is a major component of fetal bovine serum.
Blood platelets store growth factors (i.e. mitogens) in secretory (exocytotic) vesicles called α-granules. As platelets aggregate to form the blood clot matrix, the α-granules fuse with the plasma membrane to release (i.e. secrete) growth factors to attract fibroblasts to the wound site and stimulate their proliferation. The growth factors serve as ligands that bind complimentary cell-surface receptors on the fibroblasts. Examples of such growth factors include platelet-derived growth factor (PDGF), and epidermal growth factor (EGF). Unlike the cellular components of blood, growth factors secreted by platelets are contained within the serum, and are responsible for promoting proliferation when supplemented into cell culture media. In addition to growth factors, the globular protein, bovine serum albumin (BSA), is a major component of fetal bovine serum.