The W6D3 monoclonal antibody specifically binds to 3-fucosyl-N-acetyllactosamine (3-FAL), a 220 kDa carbohydrate structure, also called X-hapten. 3-FAL is expressed on >95% of granulocytes, including neutrophils and eosinophils, and on monocytes to a varying degree, but not on lymphocytes or basophils. CD15 plays a role in mediating phagocytosis, bactericidal activity and chemotaxis. Most CD15 antibodies are IgM isotype; clone W6D3 is a mouse IgG1 isotype. In comparison studies with clone HI98, a known CD15 antibody, clone W6D3 shows brighter fluorescence staining and its binding can be blocked by clone HI98.
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.