FcR Blocking Reagent for human has high affinity receptor for IgG (Fc RI, CD64) but it is not an anti-CD64, which allows its use with pure antibodies. Aplication Reference|Calvo-Iglesias et al. Characterization of a Monoclonal Antibody Directed against Mytilus spp Larvae Reveals an Antigen Involved in Shell Biomineralization. 2016 Plos One.