An international prize has been awarded for British research that could prevent many thousands of animals suffering in laboratories.
Scientists have grown "mini-livers" from mouse stem cells that can be used for testing new liver disease treatments.
The technique could reduce the number of animals needed to test 1,000 drug compounds by up to 50,000.
The £18,000 prize was awarded by the UK's NC3Rs centre that promotes advances in the 3Rs - the replacement, refinement and reduction of animals in research research.
Dr Meritxell Huch, from Cambridge University's Gurdon Institute, who developed the "mini-liver" testing method, said: "Typically a study to investigate one potential drug compound to treat one form of liver disease would require up to 50 live animals per experiment, so testing 1,000 compounds would need 50,000 mice.
"By using the liver culture system I developed, we can test 1,000 compounds using cells that come from only one mouse, resulting in a significant reduction in animal use.
"If other laboratories adopt this method, then the impact on animal use in the liver research field would be immediate. A vast library of potential drug compounds could be narrowed down to just one or two very quickly and cheaply, which can then be tested further in an animal study."
The team has further refined the technique using liver cells from rats and dogs, and is now looking at expanding the process to human cells.
NC3Rs chief executive Dr Vicky Robinson said: " Growing functioning liver cells in culture has been the Holy Grail for liver biologists for many years, so a limitless supply of hepatocytes (liver cells) could have a huge 3Rs impact both on basic research to understand liver disease and for the screening and safety testing of pharmaceuticals.
"Researchers need to utilise this alternative technology as soon as possible to ensure the benefits to animals and human health are fully realised."