1. Scottish National Blood Transfusion Service Edinburgh UK
2. Welsh Blood Service Pontyclun UK
3. Cambridge University Hospitals NHS Foundation Trust Cambridge UK
4. Gartnavel General Hospital Glasgow UK
5. Manchester Royal Infirmary Manchester UK
6. National Blood Service Tooting London UK
7. Northern Ireland Blood Transfusion Service Belfast UK
8. Oxford University Hospitals NHS Foundation Trust Oxford UK
9. Birmingham Blood Donor Centre Birmingham UK
10. Barts Health Pathology Service London UK
11. Guy's and St Thomas' NHS Foundation Trust London UK
12. Imperial College Healthcare NHS Trust London UK
13. National Blood Service Newcastle‐upon‐Tyne Newcastle upon Tyne UK