The SY/11B5 monoclonal antibody specifically binds to CD157 which is also known as BST-1 (Bone marrow stromal antigen 1), BP-3/IF-7, Mo5, ADP-ribosyl cyclase 2, and cADPr hydrolase 2. CD157 is a 40-46 kDa glycophosphatidylinositol-linked cell membrane glycoprotein. It is an ectoenzyme that has both cyclic ADP-ribose hydrolase and ADP-ribosyl cyclase activities. CD157 is expressed as a homodimer by a variety of cell types including bone marrow stromal cells, granulocytes, monocytes, macrophages, dendritic cells, endothelial cells, and B and T cell progenitors. In addition to its ectoenzyme activities, CD157 reportedly functions as a receptor involved in neutrophil and monocyte adhesion, transendothelial migration and diapedesis and in tumor cell migration.
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.