The SN2 monoclonal antibody specifically recognizes a 37-42 kDa membrane glycoprotein expressed on a subset of peripheral lymphocytes, monocytes, immature thymocytes and on most platelets. CD165, also known as gp37 or AD2, is expressed at low levels on most thymocytes and thymic epithelial cells. CD165 has been detected on islet cells of the pancreas, Bowman's capsule of the kidney and on central nervous system neurons. SN2 antigen has been reported to be identical, or very similar, to the T-cell acute lymphoblastic leukemia antigen, TALLA-1. CD165 has been reported to play a role in the adhesion between thymocytes and thymic epithelial cells during development.
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.