1. UK NEQAS for Leucocyte Immunophenotyping; Department of Haematology, Royal Hallamshire Hospital; Sheffield England
2. Immunology Quality Assessment, Duke University; Durham, North Carolina USA
3. Department of Pathology, Peter MacCallum Cancer Centre; East Melbourne Victoria Australia
4. DeePath Medical Inc.; Palo Alto CA 94301 USA
5. Genoptix Medical Laboratory; Rutherford Carlsbad California USA
6. Mayo Clinic College of Medicine, Department of Laboratory Medicine and Pathology; Rochester Minnesota