Since the 1960s, fetal calf serum (FCS) has been the “gold standard” in cell culture. It is the main component of many culture media required for the growth and cultivation of animal cells outside a living organism. This is used in medical research, for example, to support the development of drugs and vaccines. According to an estimate from 2021, the global annual demand was approximately 800,000 liters of fetal calf serum (https://pmc.ncbi.nlm.nih.gov/articles/PMC8349753/). At the UKB, approximately 800 liters of FCS were consumed in 2024.
Fetal calf serum – what's the problem?
To obtain FCS, blood is drawn directly from the still-beating hearts of unborn calf fetuses using a cannula. FCS must be sourced from outside the EU, as the EU directive prohibits its production due to the severe animal suffering involved. On the one hand, cell culture experiments using FCS are intended to reduce animal testing and thus animal suffering; on the other hand, the use of FCS is not an ideal solution from either a scientific or an animal welfare perspective.
Will research suffer if FCS is discontinued?
No, because the use of FCS also has its drawbacks. The composition of sera is very complex, and their essential components vary widely. Serum-free culture media, on the other hand, have a clearly defined composition. Their use therefore eliminates the need for time-consuming and costly testing of new batches and increases the reproducibility of experiments. Furthermore, the use of a bovine product in clinical research involving human and mouse-like cells should be viewed critically.
“Replace, Reduce, and Refine” by FCS: What can we do at the UKB?
Alternatives already exist that can reduce annual consumption of bovine fetuses by either cutting back on their use or completely replacing them—in line with the 3R principle (replace, reduce, refine). The Genetic Engineering Office, together with the Vice Dean’s Office for Sustainability at the Faculty of Medicine and the 3R Competence Network NRW, is launching a project to promote a more sustainable use of FCS at the UKB. As a first step, the team would like to collect theoretical suggestions and practical approaches for reducing FCS usage from UKB staff.
Please send your suggestions on how everyone can help conserve FCS to prodekanat.nachhaltigkeit@ukbonn.de.
Media that have already been tested specifically for certain cell lines are available at the following link.
Click here to visit the Office of the Vice Dean for Sustainability.
Online Mini-Symposium
To introduce the topic of “Animal-Free Alternatives in the Laboratory,” the 3R Competence Colloquium is hosting an online mini-symposium on the subject this month, featuring four speakers, on April 30, 2026, from 1:00 p.m. to 3:00 p.m. The event offers an ideal opportunity to learn more, exchange experiences on best practices, and gain new insights for your own work in the laboratory. Participation is free and does not require registration. You can join the Zoom webinar using these dial-in details (Webinar ID: 649 7713 9129; Passcode: 654768) or via the QR code on the announcement poster linked below. Participation in this event is certified as a continuing education hour under §3 TierSchVersV for individuals conducting and supervising animal experiments.