Alternatives and replacements

Many people want to see alternative techniques developed to replace the use of animals in research. Such techniques promise to revolutionise research and continue to replace the use of some animals. It sometimes appears that progress has been slow. But behind the scenes, biomedical research is undergoing a technological transformation. It is always a dynamic area of science, but exciting new methods range from tissue engineering to computer simulations and human studies like microdosing.


Biomedical research expanded enormously (over 50% in real terms) over the decade 1995-2005, but at the same time, animal numbers did not see a major increase (most of the increase is in breeding GM mice). In many areas of research, animal numbers have continued to fall, partly as a result of investment in alternative methods. For example, the pharmaceutical industry has eradicated whole areas of animal use by developing molecular biology and computer techniques to screen large numbers of potential medicines.

Example 1: High-tech methods
Vast investments are being made in high-tech methods of research which do not depend on animal use. One example is the recent opening of the ‘Diamond synchrotron', the result of a £ 263m collaboration between the Wellcome Trust and the UK  government. This can be used to image the structure and interactions of proteins and other molecules at an atomic scale.

Example 2: Rodents replaced by DNA technology in parasitic disease study
The debilitating parasitic disease bilharzia affects 200 million people in tropical countries. Understanding the genetic variability of the worm that causes it is important for monitoring and combatting the disease. Previously the parasites were grown by infecting rodents with parasite eggs. Recent advances in DNA technology mean that parasite samples collected directly from infected people can be studied. The technology improves the accuracy of results and is now being adopted for other parasitic diseases.

Example 3: Study of nanoparticles
New nanoparticles are so tiny that they can slip easily inside cells, with unknown consequences. Researchers showed that carbon nanoparticles killed various human cell samples in test tubes. But when researchers injected the particles into the lungs of rats, the animals' immune systems apparently removed them before any lasting damage was done. Thus how nanomaterials interact with the body is more complex than can currently be determined from cell studies alone; it requires animal research.


Exciting advances are taking place in many areas of research, from molecular biology to stem cell research, which can give detailed information on how biological systems work. But with current scientific knowledge, it would be wrong to say that all animal experiments can be replaced or phased out in the near future. It is currently recognised by the vast majority of scientists that animal studies will continue to be a vital tool in developing the next generation of new medicines.

Example 4: Eye irritation tests
Sometimes alternative test methods are inaccurate or fail to work properly. For example, much scientific work has been devoted to the search for non-animal tests to replace the Draize eye irritation test. Unfortunately, so far none of these works well enough to fully replace the existing animal test.

Validation of alternatives

Developing alternative methods is daunting, partly because it takes years to satisfy users and regulators that the results are as accurate as, or better than, animal procedures. Many researchers believe the caution is justified.

Formal validation of any alternative method for safety assessment is required. Once this has taken place, authorities should swiftly incorporate the new test into the regulatory requirements. To date, more than 30 non-animal alternative methods for assessing safety have been scientifically validated and two-thirds of these have been accepted by the regulators according to AltTox.

Get the latest articles and news from Understanding Animal Research in your email inbox every month.
For more information, please see our privacy policy.