The L138 monoclonal antibody (also known as Leu-M7) specifically binds to a glycosylated 150 kDa type II integral membrane zinc-metalloprotease. The CD13 antigen is also known as aminopeptidase N, APN, ANPEP, and gp150. The CD13 antigen is expressed on granulocytes, monocytes, mast cells, and granulocyte/macrophage progenitor cells (CFU-GM), but not on lymphocytes, platelets, or erythrocytes. It is expressed on most acute myeloid leukemia (AML) cells and some chronic myeloid leukemia (CML) cells. The CD13 antigen is also expressed on epithelial cells of the kidney, small intestine, and respiratory tract, as well as in synaptic membranes in the central nervous system (CNS). The CD13 antigen is involved in the metabolism of many regulatory peptides. Clustering of the CD13 antigen by various forms of ligation promotes the adhesion between monocytes and endothelial cells. The CD13 antigen is the receptor for human coronavirus 229E, the causative agent for some cases of upper respiratory infection.
The antibody was conjugated to BD Horizon™ BV650 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 650-nm. BD Horizon BV650 can be excited by the violet laser and detected in a filter used to detect APC-like dyes (eg, 660/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there will be spillover into the APC and Alexa Fluor® 700 detectors. However, the spillover can be corrected through compensation as with any other dye combination.