The C9Mab-1 monoclonal antibody specifically binds to Chemokine (C-C motif) receptor 9 (CCR9), which is also known as CD199. CCR9 is an ~42 kDa seven-transmembrane protein in the G protein-coupled receptor (GPCR) supergene family. It is upregulated by CD4+CD8+ double-positive thymocytes, then downregulated in committed CD4+ or CD8+ single-positive thymocytes. CCR9 is also expressed on small intestinal B cells, subsets of memory CD4+ T cells and CD8+ T cells, and dendritic cells. CCR9 binds CCL25, which is also known as thymus-expressed chemokine (TECK) or small inducible chemokine 25 (Scya25). CCL25 is highly expressed in the thymic cortex and small intestinal epithelium. CCR9 is involved in T cell development and gut-associated immune functions via lymphocyte recruitment to the gastrointestinal tract.
The antibody was conjugated to BD Horizon BUV737 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 737 nm. BD Horizon Brilliant BUV737 can be excited by the ultraviolet laser (355 nm) and detected with a 740/35 nm filter. Due to the excitation of the acceptor dye by the red laser line, there may be significant spillover into red laser detectors with filters in the 700-720 nm range.