Artificial human skin can be grown in test tubes and deliver more accurate results than testing chemicals on animal skin. Microdosing is the distribution of doses of substances just high enough to study the cellular response. Reactions can then be seen in human volunteers when their blood is analyzed. Computer models can predict the toxicity of substances without invasive experiments on animals. Microfluidic chips are lined with human cells, and replicate the way human organs function. They are in advanced stages of