- anti-PF4/Heparin IgG antibody with human Fc fragment,
- induces heparin- and FcϒRIIA-dependent platelet activation,
- specific to the PF4/Heparin complex with very low reactivity against PF4 alone.
5B9 clinical research on HIT functional assays covers the following objectives:
- identification of “good” or “bad” platelet donors responders, 
- evaluation of platelet reactivity, 
- preparation of positive samples. 
5B9 may be also used as a specific tool when studying FcϒR-dependent cell activation in the pathophysiology of HIT. 
Kits are available in stock to order
The following table summarizes the minimal final 5B9 concentration in the sample for which each assay gives positive results:
1. KIZLIK-MASSON C., VAYNE C., MCKENZIE S.E., POUPON A., ZHOU Y., CHAMPIER G. POUPLARD C., GRUEL Y., ROLLIN J.: “5B9, a monoclonal antiplatelet factor 4/heparin IgG with a human Fc fragment that mimics heparin-induced thrombocytopenia antibodies”. J.Thromb. Haemost., 15, 2065-2075, 2017.
2. VAYNE C., GUERY E.A., CHARUEL N., BESOMBES J., LAMBERT W.C., ROLLIN J., GRUEL Y., POUPLARD C.: “Evaluation of functional assays for the diagnosis of heparin induced thrombocytopenia using 5B9, a monoclonal IgG that mimics human antibodies”. J. Thromb. Haemost., 18, 968-975, 2020.
3. Can 5B9, a monoclonal anti-PF4/heparin IgG, be used as an internal quality control for HIT platelet functional assays? Présentation Y Gruel SSC Platelet Immunology ISTH 2020.