The AER-37 (CRA-1) monoclonal antibody specifically recognizes FcεRIα which is also known as the high affinity immunoglobulin epsilon receptor subunit alpha (Fc-epsilon RI-alpha). FcεRIα is a type I transmembrane glycoprotein that is encoded by FCER1A (Fc fragment of IgE receptor Ia) which belongs to the Ig gene superfamily. FcεRIα serves as the binding subunit for the Fc region of IgE. It forms part of a heterotetrameric, high-affinity IgE Fc receptor (FceR1/FcεR1) that includes signal transducing subunits, one β-chain (FcεRIβ encoded by MS4A2) and two disulfide-linked γ-subunits (FcεRIγ encoded by FCER1G). FcεRIα is normally expressed on basophils and mast cells and can also be expressed on some monocytes, Langerhans cells, dendritic cells, and eosinophils from allergic donors. FcεRIα plays a major role in allergic responses and in the presentation of allergens to the immune system. The AER-37 antibody reportedly does not compete with IgE for FceR1 binding.
The antibody was conjugated to BD Horizon BUV615 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome with an Ex Max near 350 nm and an Em Max near 615 nm. BD Horizon Brilliant BUV615 can be excited by the ultraviolet laser (355 nm) and detected with a 610/20 filter and a 595 nm LP. Due to the excitation of the acceptor dye by the blue/yellow-green laser line, there may be significant spillover into channels detecting PE-CF594 like emissions (eg, 610/20-nm filter).