The Leibniz Institute “German Collection of Microorganisms and Cell Cultures (DSMZ) GmbH” is one of the world's largest bioresource centers. Its Tumor Biology Working Group within the Department of Human and Animal Cell Cultures, led by Dr. Sonja Eberth, has adapted four commonly used human cancer cell lines (HELA, HL-60, K-562, JIMT-1) to various animal-component-free media. Human platelet lysate, as well as various fully chemically defined media, now serve as substitutes for fetal calf Serum (FCS), which has long been controversial for scientific and animal welfare reasons. 

Millions of laboratories around the world still use fetal calf serum (FCS) to grow or culture their cells. Even when they purchase cells, in most cases these are still supplied with FCS. However, the production of FCS is associated with extreme animal suffering. FCS is primarily sourced from countries where cattle farming is intensive, such as Brazil, Argentina, or South Africa. In many cases, the cows arrive at the slaughterhouse while pregnant, where the mother is stunned with a bolt gun and—often suspended by one leg—killed by bleeding out. Before the fetus dies, a thick needle is inserted through the ribs into the still-beating heart of the calf fetus without anesthesia, and about half a liter of blood is drawn from each animal.

Whole blood consists of 45% blood cells and 55% plasma. This plasma is composed of clotting factors and what is known as serum. If the cells are removed from the blood by centrifugation and the clotting factors are precipitated out, the resulting substance—serum—plays an important role in cell culture, among other things. ⁽¹⁾ This is how FCS is obtained. 

However, FCS is a mixture of undefined and variable composition, which is why FCS production is subject to significant quality fluctuations that can substantially impair the reproducibility of cell culture experiments. Problems arising from batch, geographical, and seasonal variations, as well as interspecific differences between laboratories in the handling of FCS, were already identified and described by the European validation authority EURL-ECVAM in 2008. The serum can, for example, suppress the inflammatory mediator TNF-α and thus lead to incorrect results, for instance in the field of immunological research. ⁽²⁾

Original publication: Koelz, A. L., Pommerenke, C., Woitschewski, P., Merkhoffer, Y., Dirks, W. G., & Eberth, S. (2026). Multiparametric evaluation of different FBS-free replacement media for widely used human cancer cell lines. ALTEX - Alternatives to Animal Experimentation. https://doi.org/10.14573/altex.2512111

Source and further information:
https://www.dsmz.de/press/press-releases/singleview/weniger-tierleid-in-der-krebsforschung-durch-fks-freie-zellkulturmodelle

Additional information on fetal calf serum, its substitutes, and the role of platelets:
⁽¹⁾ https://www.invitrojobs.com/index.php/en/research-and-methods/working-group-a-portrait/item/1780-working-group-a-portrait-renal-molecular-physiology-at-the-medical-university-of-innsbruck
⁽²⁾ https://www.invitrojobs.com/index.php/de/neuigkeiten/news-archiv/item/2250-workshopbericht-serum-freie-medien-sind-besser-als-foetales-kaelberserum