The 7C3.rMAb is a recombinant monoclonal antibody that specifically recognizes human CD15 which is a terminal carbohydrate epitope, 3-fucosyl-N-acetyllactosamine (3-FAL), on cell surface glycoproteins or glycolipids. CD15 is also known as Lewis X (LeX), X-Hapten, or Stage-Specific Embryonic Antigen-1 (SSEA-1). The 7C3.rMAb was derived from the 7C3 (also known as, PMN7C3) hybridoma. The 7C3 antibody was validated at HLDA V (Workshop Number MA88). The 7C3.rMAb has the same IgV-region heavy chain domain and Ig, κ light chain as the original mouse 7C3 IgG3, κ antibody. The remaining Ig constant heavy chain of 7C3.rMAb is derived from the mouse IgG1 heavy chain. CD15 is expressed on a variety of cell types including neutrophils, eosinophils, monocytes, macrophages, mast cells, and Langerhans cells. CD15 is also expressed on some epithelial cells, activated lymphocytes as well as tumor cells. CD15 is not expressed by platelets or erythrocytes. CD15 plays various roles in mediating cellular adhesion, activation, migration, and phagocytosis.
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.