The 162-46 monoclonal antibody recognizes human Trop-2 which is also known as GA733-1. Trop-2 is encoded by TACSTD2 (tumor-associated calcium signal transducer 2). It is a single-pass type-1 transmembrane glycoprotein. Trop-2 was originally identified to be expressed on human trophoblast and choriocarcinoma cell lines. Trop-2 is expressed in most human carcinomas. Trop-2 appears to be involved in the transduction of an intracellular calcium signal, although the exact physiological mechanism has yet to be elucidated.
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.