The p282 (HI9) monoclonal antibody specifically binds to CD59, a 19 kDa glycosylphosphatidylinositol (GPI)-anchored glycoprotein, expressed on hematopoietic and non-hematopoietic cells. Because of its interaction with complement activated products, CD59 has been termed membrane-attack-complex-inhibitory factor (MACIF), homologus restriction factor (HRF20), membrane inhibitor of reactive lysis (MIRL) and Protectin. It inhibits the cytolytic activity of the complement system by binding to C8 and C9, thereby blocking the assembly of the membrane attack complex. CD59 also participates in spontaneous T-cell/erythrocyte adhesion, interacts with CD2, and plays a role in T-cell activation.
The antibody was conjugated to BD Horizon BUV661 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 661-nm. BD Horizon Brilliant BUV661 can be excited by the ultraviolet laser (355 nm) and detected with a 670/25 filter and a 630 nm LP. Due to cross laser excitation of this dye, there may be significant spillover into channels detecting APC-like emissions (eg, 670/25-nm filter).