The WM59 monoclonal antibody specifically binds to platelet endothelial cell adhesion molecule-1, (PECAM-1, PECAM1), which is also known as GPIIA', or EndoCAM. CD31 is a 130 kDa type I transmembrane glycoprotein that belongs to the Ig gene superfamily. CD31 has wide tissue distribution and is expressed on platelets, monocytes, granulocytes, NK cells, T cell subsets, and in high amounts on endothelial cells. CD31 functions as a vascular endothelial cell adhesion molecule and is involved in the transendothelial migration of leucocytes in inflammatory responses. It might be involved in thrombosis, angiogenesis, and wound healing. The WM59 appears to recognize an epitope proximal to extracellular domain 2 of CD31.
Clone WM59 also cross-reacts with peripheral blood platelets and leukocytes of baboon, and both rhesus and cynomolgus macaque monkeys. The staining intensity of WM59+ platelets is similiar to that observed with peripheral blood platelets from normal human donors. Lymphocytes, monocytes, and granulocytes react less with WM59 than normal human leukocytes.
The antibody was conjugated to BD Horizon BB700, which is part of the BD Horizon Brilliant™ Blue family of dyes. It is a polymer-based tandem dye developed exclusively by BD Biosciences. With an excitation max of 485 nm and an emission max of 693 nm, BD Horizon BB700 can be excited by the 488 nm laser and detected in a standard PerCP-Cy™5.5 set (eg, 695/40-nm filter). This dye provides a much brighter alternative to PerCP-Cy5.5 with less cross laser excitation off the 405 nm and 355 nm lasers.