The 563 monoclonal antibody specifically binds to CD34. CD34 is a single-chain 105-120 kDa heavily O-glycosylated transmembrane glycoprotein expressed on hematopoietic progenitor cells, vascular endothelium and some tissue fibroblasts. The intracellular chain of the CD34 antigen is a target for phosphorylation by activated protein kinase C suggesting that CD34 may play a role in signal transduction. CD34 may play a role in adhesion of specific antigens to endothelium. Clone 563 belongs to the class III epitope; it is resistant to neuraminidase, chymopapain and glycoprotease. This antibody is able to block the binding of other CD34 mAbs like 581.
The antibody was conjugated to BD Horizon™ BV711 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 711-nm. BD Horizon BV711 can be excited by the violet laser and detected in a filter used to detect Cy™5.5 / Alexa Fluor® 700-like dyes (eg, 712/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there may be moderate spillover into the Alexa Fluor® 700 and PerCP-Cy5.5 detectors. However, the spillover can be corrected through compensation as with any other dye combination.