The R3-242 monoclonal antibody specifically binds to aminopeptidase N (APN), which has been reported to be the mouse CD13 homologue. APN is expressed in a variety of mammalian tissues, including intestinal and renal epithelial brush border, endothelium, liver, lung, and brain. In lymphoid tissues, R3-242 mAb is reported to detect APN on monocytes, macrophages, mast cells, dendritic cells, and B lymphocytes, but not on T cells, and thymocytes. However, the reported reactivity with B cells may be non-specific, via binding to the Fcγ receptors (CD16/CD32). This observation is in agreement with reports using different antibodies to mouse APN. APN may play a role in antigen presentation in the immune system. R3-242 mAb does not inhibit the enzymatic activity of APN.
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).