The 4FR6D3 monoclonal antibody specifically recognizes CD334 which is also known as Fibroblast growth factor receptor 4 (FGFR4), Tyrosine kinase related to fibroblast growth factor receptor (TKF), or JTK2. CD334 is a ~110 kDa type I transmembrane glycoprotein that belongs to the fibroblast growth factor receptor (FGFR) in the Ig superfamily (IgSF). The ligand-binding extracellular domain has three immunoglobulin-like C2-type domains followed by a transmembrane region and a cytoplasmic tail which contains a tyrosine kinase domain. CD334 serves as a high affinity receptor that dimerizes upon binding to fibroblast growth factors including FGF-1, -2, -4, -6, -8, -9, -16, -17, -18, and -19. This cell surface receptor tyrosine kinase is widely expressed on epithelial cells, fibroblasts and skeletal muscle cells and plays a role in the proliferation, differentiation, migration, and survival of these different cell types. Abnormal expression and activity of CD334 has been associated with a number of different cancers.
The antibody was conjugated to BD Horizon BUV615 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome with an Ex Max near 350 nm and an Em Max near 615 nm. BD Horizon Brilliant BUV615 can be excited by the ultraviolet laser (355 nm) and detected with a 610/20 filter and a 595 nm LP. Due to the excitation of the acceptor dye by the blue/yellow-green laser line, there may be significant spillover into channels detecting PE-CF594 like emissions (eg, 610/20-nm filter).