Safety issues of animal products used in serum-free media.

The development of media free of serum and animal or human protein is of utmost importance for increasing the safety of biologicals produced for therapy and vaccination. The main drawback associated with the use of serum or animal-derived substances for animal cell technology is the potential introduction of contaminants (adventitious agents) into the process and thus potentially into the final product. This fact led to an increased effort to replace serum-containing with serum-free media. In most cases, these media are supplemented with purified proteins, peptones, or hydrolysates, mainly of animal or human origin. Although such serum-free media are more defined than serum-containing media, the risk of the introduction of viruses by using animal-derived substances is still present, signifying that only a complete replacement of animal-derived substances by non-animal-derived products leads to a relatively safe serum-free medium. The potential replacement of these animal/human-derived substances by those of non-animal origin (e.g. plant origin) will be discussed. In several examples, the potential of serum-free media free of any animal-derived component in supporting cell growth and production of biologicals will be presented. In this context, the risk of using non-animal-derived substances in serum-free media for animal cell technology will be discussed with respect to classically used cell culture media.