In 2022 Animal Aid provided funding to XCellR8, the world’s only vegan laboratory, to develop their AcutoX test – a replacement for the cruel and outdated LD50.
Not only does XCellR8 not use any live animals but its work doesn’t involve any animal tissue, cells or other animal products.
What's wrong with lethal dose testing on animals?
What are Animal Aid doing?
The LD50 test, originally designed in 1927, stands for ‘lethal dose 50%’. It involves giving live animals increasing doses of a substance until half of them die. This informs scientists of a substance’s ‘lethal dose’.
Despite major advances in animal-free toxicology, the LD50 and similar tests continue to use millions of animals every year – including thousands in Britain. Symptoms include tremors, convulsions, swellings, bleeding from the mouth and nose, bulging eyeballs and difficulty breathing.
Animal Aid was founded in 1977 to campaign against animal experiments, and our earliest years were dedicated to the LD50. More than 45 years later, when alternatives exist, it’s time this test was banned.
The team at XCellR8 has developed the world’s first alternative to the cruel and outdated LD50 test. But what does it involve?
Scientists at the XCellR8 laboratory add a number of human skin cells into a small ‘well’ on the surface of a special tile. This tile contains many ‘wells’ –a bit like having lots of test tubes on a plate!
The cells are then incubated at 37 °C in 5% CO2, which mimics the conditions in the human body.
Once the cells are ready for the test, they are treated with chemicals. After 24 hours, the cells are washed and observed. Comparing the various cells – those that received the test chemical and those that did not – allows scientists to determine the lethal dose of the substance being tested, all without harming animals.

Take action for animals in laboratories
Science shouldn’t involve sacrifice, either to the quality of work or the lives of animals. Better science is possible, and we’re immensely proud to be working with XCellR8 to make it a reality.