Flow Cytometry Blocking Controls

Fc receptors are found on monocytes, macrophages, dendritic cells and B cells. As the name suggests they bind antibodies via their constant Fc domain rather than the antigen specific Fab domain.

This type of binding can lead to false positives and meaningless data. In order to prevent this type of binding, Fc blocking reagents (e.g. Human Fc Seroblock and Murine Fc Seroblock) have been developed which, when added to a staining protocol, can ensure that only antigen specific binding is observed.

Fig. 21. Fc blocking. THP-1 cells stained with mouse anti human CD11a (blue) or mouse IgG2a isotype control (MCA929F) (red) in the absence (A) and presence (B) of human Seroblock (BUF070A)