For Research Use Only. Human Factor IX Inhibitor, lyophilized. Plasma Factor Inhibitor Plasmas are produced from normal human plasmas from which specific factors have been removed by selective affinity immuno-adsorption and an antibody inhibitory to the specific factor is added to provide neutralizing activity. This product must be purchased in quantities of 10. Can be used as a substitute for plasmas from patients that have developed neutralizing antibodies to coagulation factors and can be used as positive controls in factor inhibitor assays.