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™ BV650 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 650-nm. BD Horizon BV650 can be excited by the violet laser and detected in a filter used to detect APC-like dyes (eg, 660/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there will be spillover into the APC and Alexa Fluor® 700 detectors. However, the spillover can be corrected through compensation as with any other dye combination.