The S7 monoclonal antibody specifically binds to the 115 kDa glycosylated form of CD43 (Ly-48, Leukosialin). CD43 is expressed on IL-7-responsive pro-B cells, plasma cells, peritoneal and splenic CD5+ B cells (B-1 cells), granulocytes, monocytes, macrophages, platelets, natural killer cells, thymocytes, peripheral T cytotoxic/suppressor cells, and most T helper cells, but not resting conventional peripheral B cells. CD43 expression has also been detected on pluripotent hematopoietic stem cells and myeloid, lymphoid, and NK-cell progenitors in the bone marrow. Studies of CD43-deficient mice indicate that CD43 participates in the negative regulation of T-cell activation and adhesion.
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.