1. Biosystems and Biomaterials Division; NIST (National Institute of Standards and Technology); Gaithersburg Maryland 20899
2. Biotherapeutics Group; NIBSC (National Institute for Biological Standards and Control); Blanche Lane South Mimms Potters Bar Hertfordshire EN6 3QG United Kingdom
3. Division of Medical Physics and Metrological Information Technology; PTB (Physikalisch-Technische Bundesanstalt); Berlin 10587 Germany
4. Abbott GmbH & Co. KG; Germany
5. Department of Analytical Chemistry; BAM Federal Institute for Materials Research and Testing; Berlin D-12489 Germany
6. Beckman Coulter GmbH; Europark Fichtenhain B13 Krefeld 47807 Germany
7. Becton Dickinson; Tullastraße 8-12 Heidelberg 69126 Germany
8. Medicinal and Process Chemistry Division; CDRI (Central Drug Research Institute); Chattar Manzil Palace, Mahatma Gandhi Marg Lucknow Uttar Pradesh 226001 India
9. CDRH/FDA (Center for Devices and Radiologic Health Food and Drug Administration); Bethesda Maryland 20892
10. Amount of Substance; INRIM (Istituto Nazionale Di Ricerca Metrologica); Strada Delle Cacce 91 Torino 10135 Italy
11. Bioanalysis, KRISS (Korea Research Institute of Standards and Science); Doryong-Dong Yuseong-Gu Daejeon 305-340 Korea
12. Science and Innovation; LGC Limited; Teddington Middlesex TW11 0LY United Kingdom
13. UK NEQAS (UK National External Quality Assessment Service); Sheffield South Yorkshire S10 2QD United Kingdom
14. Division of Medical and Biological Measurement; NIM (National Institute of Metrology); No 18, Bei San Huan Zhong Lu Beijing China
15. Partec GmbH; Muenster 48161 Germany
16. Department of State Standards in the Field of Physical-Chemical Measurements; VNIIM (D.I. Mendeleev Institute for Metrology), Moskovsky Pr., 19, 190005, St-Petersburg Russia and Biomedical Technologies, Institute of Cytology, Russian Academy of Science; 194064 St-Petersburg Russia