Which do you think better approximates a human being: disembodied human cells in a Petri dish, or mouse cells in a live, sniffling rodent?

A multi-institutional collaboration has been formed to find out. The US National Institutes of Health and the Environmental Protection Agency announced today that they will try to determine whether computer models, cell cultures, and zebrafish can replace mice, rats, and guinea pigs in toxicology tests.

They’ll start by treating cell cultures with chemicals for which animal toxicity data is already available, to gain a sense of how well results from the two systems match. The shift to cell cultures promises several advantages, including high speed. Christopher Austin, director of the NIH Chemical Genomics Center, says their labs can test 2500 chemicals at 15 different concentrations in a single afternoon using cell cultures. Testing the same number of chemicals in animals has taken thirty years, he said.

But you cannot abandon animal testing overnight, cautioned Elias Zerhouni, director of the National Institutes of Health. The agency officials declined to estimate when their comparisons would be complete.