Fc receptors are glycoproteins with a molecular weight of approximately 50-70 kDa. They include FcγR (IgG), FcεRI (IgE), FcαRI (IgA), FcμR (IgM), and FcδR (IgD). Within the immune system, Fc receptors are highly expressed on various cell types, including monocytes, granulocytes, B cells, and dendritic cells. In biomedical experiments such as cell sorting, immunohistochemistry, immunofluorescence, and flow cytometry, non-specific binding to Fc receptors can cause the Fc regions of primary and secondary antibodies to bind to Fc receptors on cells. This introduces significant experimental error, making it crucial to eliminate Fc receptor interference to obtain accurate results.