The U21-1283 monoclonal antibody specifically recognizes Neuropilin-1 (NRP1), also known as CD304, Blood dendritic cell antigen 4 (BDCA4), and Vascular endothelial cell growth factor 165 receptor (VEGF165R). CD304 is a type I transmembrane glycoprotein involved in the development of the nervous and cardiovascular systems. It mediates the interaction, growth, survival, and migration of a variety of normal and tumor cells. CD304 is expressed on neurons, thymocytes, regulatory T cells, a subset of T follicular helper cells, dendritic cells, endothelial cells, and certain tumor cells. Neuropilin-1 has a very short cytoplasmic domain and interacts with various coreceptors to form ligand-binding, signal-transducing receptor complexes. CD304 complexes with Plexin-A family members to bind chemorepellent Class 3 Semaphorins and guide neuronal axon growth. It also functions as a coreceptor with VEGFR2/CD309 to stimulate angiogenesis in response to VEGF165. CD304 mediates the interactions between some T cells and dendritic cells.
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).