The 346-11A monoclonal antibody specifically recognizes an epitope at the beginning of the cysteine-rich repeat region of the 200-kDa integrin β4 chain (CD104), which is found on the cell surface as a heterodimeric complex with the integrin α6 chain (CD49f). The α6β4 (CD49f/CD104) complex binds to laminins and is expressed on the basal surface of a variety of epithelial cell types, particularly on stratified squamous epithelia, and is also found in peripheral nerves, in certain subsets of endothelial cells, and on immature thymocytes. It has also been identified on a number of tumor tissues and participates in tumor progression events. Localization of both human and mouse epidermal α6β4 integrin to hemidesmosomes suggests that this heterodimer plays a role in epidermal adhesion to the basement membrane.
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.