Genetically modified mice.


Animal research legislation

UK animal research is governed by the Animals (Scientific Procedures) Act 1986 Amended Regulations 2012 (A(SP)A) and regulated by the Home Office (a branch of the UK government).

Under A(SP)A animal research must:

  • be carried out at a licensed establishment
  • be part of a licensed project 
  • be conducted by an investigator with their own personal licence, and who is competent in the procedures on live animals.

Home Office inspectors visit facilities regularly to ensure full compliance with A(SP)A and good practice.

The Crick is a signatory of the Concordat on Openness on Animal Research, which sets out how organisations report the use of animals in scientific, medical and veterinary research in the UK.

Animals (Scientific Procedures) Act 1986

Severity levels

We consider all animal work at the Crick carefully, weighing the potential benefits of the research against the potential harm to the animals, as per our Animals in Research Policy.

Before any work involving animals begins, our Animal Welfare and Ethical Review Body (AWERB) scrutinises it to ensure that the researchers can only answer their scientific question by using animals, that the experiments cause as little harm to the animals as possible, and all measures are taken to minimise animal suffering like the appropriate use of anaesthesia and analgesia (pain relief) and the use of sterile conditions in surgical procedures. 

A(SP)A recognises four categories of suffering: 'sub-threshold', 'mild', 'moderate' and 'severe' and a fifth category, 'non-recovery'.

Sub-threshold: The procedure has a negligible impact on the animal's wellbeing

For example, a mouse is given a compound present in broccoli alongside their normal mouse diet to see if the compound helps the animal's gut. The compound doesn't affect the food intake, and after three months the mouse was humanely killed and its gut was analysed.

Non-recovery: The procedure is done under general anaesthetic and the animal is humanely killed before it wakes up

For example, a healthy genetically altered mouse was put under anaesthetic. Electrodes were inserted into its brain to record brain cell signals while the mouse was kept unconscious. Once the recordings were complete, the animal was humanely killed while still under anaesthetic.

Mild: The procedure only causes minor, short-term pain or distress with no lasting impact

For example, a mouse was given a modified low-protein diet for four weeks after weaning. At the start of the experiment, a drop of blood was collected by pricking a tail vein. This was repeated after two weeks and four weeks. The mouse was humanely killed, and tissue was collected to study the effect of a low-protein diet on organ development during the first four weeks after weaning.

Moderate: The procedure may cause pain, distress or discomfort and a noticeable difference to the animal's natural state, but they are able to move, eat and drink relatively normally

For example, a genetically altered zebrafish was used for egg collection. Over time, it developed a curved spine, which compromised its normal movements. The animal was humanely killed when the curvature became apparent.

For example, a mouse was given a flu virus by inhalation. The mouse became unwell, was less active and ate less for two days. This resulted in a 10% loss in body weight. Before and during the infection, blood samples were collected for analysis. The mouse recovered completely after five days, and was kept for further blood testing for another three months and was then humanely killed before tissue was collected for further analysis.

Severe: The procedure has a major impact on the animal's health and wellbeing, and they don't live or behave normally. They might experience a significant level of pain, distress or discomfort. 

For example, a mouse had surgery to remove its thymus before further studies. The mouse recovered completely from the anaesthetic, but the following morning it was reluctant to move and was not eating or drinking. The animal was then humanely killed. 

For example, a genetically altered mouse was injected with tumour cells. As the tumour grew, it was monitored using regular MRI scans with the mouse under anaesthetic. Six weeks into the study, the mouse was unexpectedly found dead after showing no signs of suffering. Post mortem analysis found that the tumour had also grown into the heart, which wasn't visible on the MRI scans.

Ethical review

Our Animal Welfare and Ethical Review Body (AWERB)'s function is divided between several committees to ensure it fulfils its responsibilities. The AWERB is led by the Biological Research Facility’s Strategic Oversight Committee (BRF-SOC), supported by three key subcommittees:

  • Production, Use, Care and 3Rs, which promotes the 3Rs, ensuring a culture of care and good practice
  • Project Licence Review, which considers applications for new project licences and amendments to existing projects to ensure that the work proposed is necessary and ethically justified
  • Animal Accommodation, Compliance and Environment, which monitors the housing conditions of animals.

Members for the committees are drawn from across the institute, and there is some crossover between committees, leading to effective decision making and communication flow. There are also procedures in place to make sure no one is involved in making decisions about their own projects.

We include non-scientists from outside the Crick on the committees, to provide an external view and challenge proposed projects that they are not comfortable with.

Several supporting groups also provide feedback to these AWERB committees: the Named Persons Forum, the Technician Discussion Group, and unit specific and function user groups.

Graphic showing the structure of AWERB

Organisational chart showing the structure of AWERB