1. Department of Medical Laboratory Diagnostics, General Hospital Bjelovar, Bjelovar, Croatia
2. Clinical Department of Laboratory Diagnostics, Clinical Hospital Center Rijeka, Rijeka, Croatia
3. Department of Laboratory Diagnostics, Children’s Hospital Zagreb, Zagreb, Croatia
4. Department of Medical Laboratory Diagnostics, General Hospital „Dr. Ivo Pedišić“, Sisak, Croatia
5. Cystic Fibrosis Centre - Paediatrics and Adults, University Hospital Centre Zagreb and University of Zagreb - School of Medicine, Zagreb, Croatia
6. Department of Clinical Laboratory Diagnostics, Children’s Hospital Srebrnjak, Zagreb, Croatia
7. Poliklinika Breyer, Zagreb, Croatia
8. Department of Medical Laboratory Diagnostics, General Hospital Šibenik, Šibenik, Croatia
9. Department of Medical Laboratory Diagnostics, General Hospital Varaždin, Varaždin, Croatia
10. Department of Medical Laboratory Diagnostics, General Hospital „Dr. Josip Benčević“, Slavnoski Brod, Croatia
11. Cinical Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia
12. Department of Medical Laboratory Diagnostics, County Hospital Požega, Požega, Croatia