1. German Red Cross Blood Service NSTOB; Springe Germany
2. National Blood Centre; Irish Blood Transfusion Service; Dublin Ireland
3. International Blood Group Reference Laboratory; NHSBT Filton Blood Centre; Bristol UK
4. Institute for Transfusion Medicine and Immunohematology; German Red Cross Blood Service Baden-Württemberg-Hessen; Baden-Baden Germany
5. Imusyn; Hannover Germany
6. Institute for Transfusion Medicine; Hannover Medical School; Hannover Germany