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?

  • 2
    $\begingroup$ As a cattle farmer, I can contribute a little to why FBS is so expensive at least. Slaughterhouses HATE receiving pregnant cattle, so they go out of their way to not buy them. Therefore stockyards avoid buying them as well, and will send a cow back to the rancher if they determine it's pregnant. This means that the number of bovine fetuses that evade detection and make it to the slaughterhouse for processing is small, which keeps the supply of FBS low and prices high. $\endgroup$
    – user137
    Commented Dec 8, 2015 at 1:04

1 Answer 1


The reason fetal bovine serum (FBS) is used is because it supports a wide variety of cells and really supports their growth. It has a high concentration of growth factors, but also a low concentration of antibodies. So it promotes growth in almost any cell or tissue type without also having antibody reactions with it.

Adult cows blood will have the opposite concentrations, higher levels of antibodies and lower levels of growth factors as they have already grown.

There are currently several research projects looking for a alternative or synthetic FBS, but nothing has worked as a total replacement. There are a few substitutes for specific purposes, but nothing with the diversity of uses that FBS has.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .