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UK alternatives group questions use of fetal calf serum
An umbrella group of UK-based organisations, which is working to advance the replacement of animal experiments, is urging researchers to think twice before using fetal calf serum (FCS). In vitro techniques have successfully reduced the number of laboratory animals used worldwide. Ironically, however, some in vitro research involves the use of a supplement for cell culture media, which is obtained from animals.
Focus on Alternatives (FoA), which includes the Dr Hadwen Trust, FRAME, the Humane Research Trust, the Lord Dowding Fund for Humane Research, the RSPCA, the St Andrew Animal Fund, and the UK Human Tissue Bank, is hoping to persuade researchers to consider using a more ethical alternative where possible - namely serum-free media.
One of FoA's key concerns centres on the techniques used to produce FCS. It is manufactured from blood that has been harvested from calves which are removed from a cow's uterus after slaughter of the dam. Usually, the blood is obtained by cardiac puncture without the use of anaesthesia.. There is increasing evidence that calves may be alive and, if they have breathed in air, may have normal brain function during the blood collection process. As a result the calves could experience suffering until death occurs (Mellor & Gregory, 2003). FCS is a popular supplement for cell culture media because it provides essential components, such as growth factors, vitamins and hormones. Currently, the demand for FCS is so high that between 1 and 2 million calves per year are required for its production. The widespread use of FCS has led FoA to begin a campaign aimed at encouraging researchers to switch to serum-free media where possible, by highlighting the animal welfare concerns and technical problems associated with FCS use.
One of the major scientific drawbacks of the use of FCS is that its components are largely undefined, making the control of cell culture conditions difficult. Laboratories may have to undertake testing on each batch before use, because of the variability between batches. In turn, batch variability can reduce the comparability of experiments and can make it difficult for studies to be reproduced. The prevention of the introduction of a biological contaminant into laboratory culture systems remains a key concern of researchers, and FCS could potentially introduce a wide range of contaminants (eg micro-organisms such as bacteria, viruses and fungi) because of the way blood is collected. Indeed, due to the risk of contamination posed by FCS, regulatory agencies already discourage or ban the use of animal sera for the production of biological products for human use. The scientific case for researchers to find a better alternative is a strong one.
From a scientific viewpoint, serum-free media have many advantages. A range of chemically defined serum-free media is available, in which many cell types can be cultured. The use of serum-free media ensures that variability between batches is minimised, and improves the comparability and repeatability of experiments. It also ensures that one potential source of biological contamination is removed. From an animal welfare perspective, whilst serum-free media, by definition, may not be free of all serum-derived products, some types of serum-free media are produced which do not involve the use of any animal products.
To encourage researchers to consider alternatives to FCS, FoA has compiled a table of suppliers of serum-free media, which can be accessed via the FoA website at www.focusonalternatives.org.uk. Serum-free media that are entirely free of animal-derived components are specifically highlighted in the table. FoA would like to invite researchers who could suggest ways in which FoA could promote the use of serum-free media further, to contact FoA via the website.
References
- Mellor, D.J. and Gregory, N.G. (2003). Responsiveness, behavioural arousal and awareness in fetal and newborn lambs: experimental, practical and therapeutic implications. New Zealand Veterinary Journal 51 2-13.