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™ BUV563 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 which has an Ex Max of 348 nm and an acceptor dye. The tandem has an Em Max at 563 nm. BD Horizon BUV563 can be excited by the 355 nm ultraviolet laser. On instruments with a 561 nm Yellow-Green laser, the recommended bandpass filter is 585/15 nm with a 535 nm long pass to minimize laser light leakage. When BD Horizon BUV563 is used with an instrument that does not have a 561 nm laser, a 560/40 nm filter with a 535 nm long pass may be more optimal. Due to the excitation and emission characteristics of the acceptor dye, there may be spillover into the PE and PE-CF594 detectors. However, the spillover can be corrected through compensation as with any other dye combination.