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 BV421 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max near 407 nm and Em Max near 421 nm, BD Horizon BV421 can be excited by the violet laser (405 nm) and detected with a 450/50 nm filter. BD Horizon BV421 conjugates are very bright, often exhibiting a 10 fold improvement in brightness compared to Pacific Blue™ conjugates. Due to nearly identical excitation and emission properties but different spillover characteristics, BD Horizon BV421, Pacific Blue™, and BD Horizon V450 cannot be used simultaneously.