Validation of in vitro cytotoxicity tests--past and present strategies

By Ekwall, B. - Bondesson, I. - Hellberg, S. - Hogberg, J. - Romert, L. - Stenberg, K. - Walum, E.

In recent years, conventional toxicity testing in animals has been reinforced by in vitro methods. As a result, toxicity testing in some sectors has become more effective and at the same time more ethical. This trend is probably only at its beginning, as many of the newly-developed methods have not yet won general acceptance as a basis for the large-scale replacement and reduction of animal experimentation. What limits the wider use of these methods is validation, i.e. the evaluation of their reliability and relevance. The present paper is a short review of the validation efforts made hitherto, including projects being planned and under discussion. Our own MEIC approach is compared with other strategies. Finally, our opinion on the effectiveness of one large consensus project relative to several different smaller validation programmes is expressed--we advocate the latter strategy, because it will save time and reduce costs.