The 3A2-2E7 monoclonal antibody (also known as SN8) specifically recognizes CD79b. Immunoglobulin (Ig) antigen receptors are composed of a non-covalently-associated complex of Ig and two other proteins, Igα and Igβ, clustered as CD79a and CD79b, respectively. CD79b is a membrane glycoprotein of 229 residues, with a predicted relative molecular mass of 36-40 kDa. Its expression is restricted to B lineage cells. CD79b reportedly associates with surface IgM and is involved in signal transduction. The 3A2-2E7 antibody has similar reactivity characteristics as clone CB3-1. The 3A2-2E7 and CD3-1 antibodies specifically react with an epitope that is enhanced on certain B-cell leukemias such as prolymphocytic leukemia and lymphoma, but not on chronic lymphocytic leukemia.
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.