The IA10 monoclonal antibody specifically binds to CD55, which is also known as complement decay-accelerating factor (DAF). CD55 is a glycophosphatidylinositol (GPI)-anchored, single chain membrane glycoprotein of approximately 70 kDa that belongs to the regulators of complement activation (RCA) gene family which includes CD21, CD35, and CD46. CD55 is widely expressed on hematopoietic cells including platelets and erythrocytes, as well as on many non-hematopoietic cells, such as, endothelial cells and epithelial cells. CD55 is involved in protecting cells from damage by autologous activated complement complexes. CD55 prevents the amplification steps of the complement cascade by interfering with the assembly of the C3-convertases, C4b2a and C3bBb, and the C5-convertases, C4b2a3b and C3bBb3b.
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.