The B6.2 monoclonal antibody reacts with a glycosylphosphatidylinositol-anchored glycoprotein present on granulocytes. Antibody B6.2 was studied as recognizing CD66c in the VI Human Leukocyte Differentiation Antigen workshop. CD66 antigens also known as the carcinoembryonic antigen (CEA) family of molecules, are closely related to the immunoglobulin super family of glycoproteins. Studies on CD66 molecules suggest a potential adhesion function in vivo. These molecules exhibit both homophilic and heterophilic adhesion. CEA family members may be involved in transmembrane signalling and activation of neutrophils. This clone has been found to be N-terminal domain reactive, reacted preferentially with the native protein and were conformationally dependent.
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).
Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BUV661 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV661 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.