Strategies for replacing animals in biomedical research.

In 1959, Russell and Burch published their recommendations for applying the Three Rs (reduction, refinement and replacement alternatives) to the use of animals in scientific experimentation. At this time, they could not have predicted the effect of this fundamental concept on academic and industrial animal experimentation and in biomedical education. Although more than 30 years have passed, their ideas are gaining respectability and wide acceptance. This article reviews the recent advances in the use of non-animal methods in biomedical research, and discusses the outlook for the further implementation of 'alternatives'.