Reason for the source of fetal bovine serum?

Question

What is the reason that perhaps the most commonly used serum in labs is fetal bovine derived? Is there something about fetal serum that is particularly useful over say serum just harvested periodically from adult cows, or cows going to slaughter?

Answer 1

Once an animal is born, their immune system starts to produce antibodies and other defense mechanisms that can cause a lot of damage to cells in a dish. Fetal calf serum has very low levels of antibodies and much higher levels of growth hormones. Both of which benefit cells in culture.