The 657909 monoclonal antibody specifically recognizes Tetraspanin-8 (TSPAN8) that belongs to the Transmembrane 4 (Tetraspanin) superfamily (TM4SF). This molecule is also known as Transmembrane 4 superfamily member 3 (TM4SF3). TSPAN8 is a protein that spans the membrane four times with transmembrane segments and has intracellular N- and C-termini. TSPAN8 has a small and a large extracellular loop that can mediate dimerization and association with other molecules including integrins, proteases, or cell signaling receptors. TSPAN8 is variably expressed on hematopoietic progenitor cells, spermatogonial stem cells, epithelial cells, and some tumor cells. TSPAN8 is involved in epithelial wound healing and may contribute to tumor cell metastasis.
The antibody was conjugated to BD Horizon™ BV650 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 650-nm. BD Horizon BV650 can be excited by the violet laser and detected in a filter used to detect APC-like dyes (eg, 660/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there will be spillover into the APC and Alexa Fluor® 700 detectors. However, the spillover can be corrected through compensation as with any other dye combination.