The 9E9 monoclonal antibody specifically binds to Fc receptor, IgG, low affinity IV (FcγRIV), which is also known as CD16-2. FcγRIV is encoded by Fcgr4 and belongs to the family of receptors for the Fc region of IgG (FcγRs), which also includes FcγRI (CD64), FcγRII (CD32), and FcγRIII (CD16) within the Ig superfamily. FcγRIV is expressed on monocytes, macrophages, dendritic cells, and neutrophils. FcγRIV, which serves as a ligand-biding subunit, requires the common Fcγ chain for expression and signaling. This complex serves as a cell activating receptor when bound by IgG2a or IgG2b. FcγRIV plays various roles in inflammation including neutrophil trafficking and mast cell degranulation. FcγRIV can also function as a low-affinity IgE receptor and promote IgE-induced inflammation. The 9E9 antibody can reportedly inhibit cellular FcγRIV (CD16-2) function and block non-antigen-specific binding of immune complexes to improve the quality of immunological assays.
This antibody is conjugated to BD Horizon™ BV605 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 407-nm and Em Max of 602-nm, BD Horizon BV605 can be excited by a violet laser and detected with a standard 610/20-nm filter set. BD Horizon BV605 is a tandem fluorochrome of BD Horizon BV421 and an acceptor dye with an Em max at 605-nm. Due to the excitation of the acceptor dye by the green (532 nm) and yellow-green (561 nm) lasers, there will be significant spillover into the PE and BD Horizon PE-CF594 detectors off the green or yellow-green lasers. BD Horizon BV605 conjugates are very bright, often exhibiting brightness equivalent to PE conjugates and can be used as a third color off of the violet laser.