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™ BUV737 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 737-nm. BD Horizon Brilliant BUV737 can be excited by the ultraviolet laser (355 nm) and detected with a 740/35 filter. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into channels detecting Alexa Fluor® 700-like dyes (eg, 712/20-nm filter).
Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BUV737 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV737 reagents (eg, CD4 vs. CD45) can have slightly different fluorescence spillover therefore, it may also be necessary to use clone specific compensation controls when using these reagents.