Bovine serum is the clear yellowish fluid that remains from whole blood after clotting. Clotting happens when fibrinogen turns into fibrin, thus enhancing the release of a perfect blend of valuable cell growth-stimulating components into the serum. Centrifugation then allows the serum to completely separate from the blood clot.
Bovine serum comes from blood taken from domestic cattle. While the procedure of making serum may seem to be straightforward, the processing of serum takes place under very tightly controlled conditions. Bovine serum is a by-product of the meat industry.

Bovine serum comes from blood collected from domestic cattle. Even though the procedures involved in separating the serum may seem to be straightforward, all the steps involved in processing serum take place under very tightly controlled conditions. Bovine serum is a by-product of the meat industry.

Bovine blood may be collected at the time of slaughter, from adult cattle, calves, newborn calves or from bovine fetuses (when cows that are slaughtered are found to be pregnant). Blood can also be collected from “donor” animals which give blood regularly. Blood is available from bovine fetuses only because a small portion of female animals that are slaughtered for meat for human consumption, are found unexpectedly to be pregnant.

Bovine serum is categorized according to the age of the animal from which the blood was collected as follows:

• Fetal bovine serum comes from fetuses
• Newborn calf serum comes from calves less than three weeks old
• Calf serum comes from calves between three weeks and 12 months of age.
• Adult bovine serum comes from cattle older than 12 months