1. Stichting KCL–Medical Center Leeuwarden, Leeuwarden, the Netherlands
2. Rijnstate Hospital, Arnhem, the Netherlands
3. Medial Laboratories, Hoofddorp, the Netherlands
4. Gelre Hospitals, Apeldoorn, the Netherlands
5. VU Medical Center, Amsterdam, the Netherlands
6. IQ Products, Groningen, the Netherlands
7. Abbott Diagnostics Division, Wiesbaden-Delkenheim, Germany