The B1.1 monoclonal antibody binds to several glycosylphosphatidylinositol-anchored glycoproteins present on granulocytes and epithelial cells. As reported in the Sixth International Workshop and Conference on Human Leucocyte Differentiation Antigens, the B1.1 antibody recognized CD66a (CEACAM1), CD66c (CEACAM6), CD66d (CEACAM3) and CD66e (CEACAM5). CD66 antigens belong to the carcinoembryonic antigen (CEA) family of molecules that are closely related to the immunoglobulin superfamily of glycoproteins. Studies on CD66 molecules suggest a potential adhesion function in vivo. These molecules exhibit both homophilic and heterophilic adhesion. CEA family members may be involved in transmembrane signaling and activation of neutrophils.
The antibody was conjugated to BD Horizon™ BUV496 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.