The EMab-134 monoclonal antibody specifically recognizes the epidermal growth factor receptor (EGF-R). The EGF-R is a transmembrane glycoprotein of approximately 170 kDa that is expressed on most cells. It consists of a glycosylated extracellular domain which binds to epidermal growth factor (EGF), a transmembrane domain, and an intracellular domain with tyrosine-kinase activity essential for signal transduction. The epitope recognized by EMab-134 is an extracellular peptide that is not affected by glycosylation. The EGF-R plays an important role in the growth and differentiation of many cellular types. Transforming growth factor α (TGFα), vaccinia virus growth factor, and related growth factors can also bind to and signal through the EGF-R.
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.