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™ 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.