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™ BUV563 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 which has an Ex Max of 348 nm and an acceptor dye. The tandem has an Em Max at 563 nm. BD Horizon BUV563 can be excited by the 355 nm ultraviolet laser. On instruments with a 561 nm Yellow-Green laser, the recommended bandpass filter is 585/15 nm with a 535 nm long pass to minimize laser light leakage. When BD Horizon BUV563 is used with an instrument that does not have a 561 nm laser, a 560/40 nm filter with a 535 nm long pass may be more optimal. Due to the excitation and emission characteristics of the acceptor dye, there may be spillover into the PE and PE-CF594 detectors. However, the spillover can be corrected through compensation as with any other dye combination.