The A8 monoclonal antibody specifically binds to CD100 which is also known as Semaphorin-4D (SEMA4D). CD100 is a 150 kDa type I transmembrane glycoprotein that belongs to the semaphorin family. CD100 is widely expressed in the nervous and immune systems. Although it is expressed on T cells, its expression is significantly upregulated on activated T cells. It is also expressed on NK cells, B cells, and monocytes. CD100 is an adhesion molecule that functions as a signaling molecule which plays a role in lymphocyte activation. CD100 interaction with CD72 enhances B cell signaling and ultimately promotes B cell activation and survival.
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.