The VI-PL2 monoclonal antibody specifically binds to CD61. CD61 is a 105 kDa transmembrane glycoprotein that is also known as integrin β3 and platelet glycoprotein IIIa (GPIIIa or GP3A). It is expressed on platelets, megakaryocytes, osteoclasts and endothelia. Integrin β3 associates with gpIIa (CD41) to form the CD41/CD61 complex which mediates platelet adhesion and aggregation. CD61 also associates with CD51 to form the CD51/CD61 complex (vitronectin receptor). CD61 appears to bind to fibrinogen, fibronectin, vWF, vitronectin, and thrombospondin to mediate cell 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.