The SGP1 monoclonal antibody specifically recognizes human ErbB3 (also known as HER-3), a 160-kDa glycoprotein that is a member of the epidermal growth factor receptor or ErbB family of receptor tyrosine kinases. Other members of the family include the epidermal growth factor receptor (EGFR, ErbB-1, HER1), ErbB-2 (Neu, HER2), and ErbB-4 (HER4). Members of this receptor family mediate the proliferation and differentiation of normal cells. They have a common structure consisting of an extracellular ligand-binding domain, a transmembrane region, and a cytoplasmic region that has sequence homology to tyrosine kinases, which is inactive in ErbB3. ErbB3 is expressed on neurons and in tissues from the digestive, urinary and respiratory tracts, the circulatory system, and female and male reproductive organs. It is overexpressed in a variety of tumors and is undetectable in hematopoietic tissue and cell lines derived from hematopoietic tumors. ErbB3 is able to form heterodimers with other ErbB family members that have active tyrosine kinases. This interaction is able to mediate signal transduction upon binding of ErbB3 to its ligand neuregulin, a cell adhesion molecule that is involved in development of the heart and nervous system.
The antibody was conjugated to BD Horizon BV750 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 750-nm. BD Horizon Brilliant BV750 can be excited by the violet laser (405 nm) and detected with a 750/30 nm filter with a 740 nm long pass. Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BV750 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended.