The TU41 monoclonal antibody specifically binds to the intracellular adhesion molecule-3 (ICAM-3) which is also known as CD50. ICAM-3 is a 110-120 kDa type I membrane glycoprotein expressed on all leukocytes (platelets and erythrocytes are ICAM-3-negative). ICAM-3 is also expressed on epidermal Langerhans cells and endothelial cells. It predominantly interacts with LFA-1 (CD11a/CD18) without requiring activation as the initial dendritic cell-T lymphocyte interaction. ICAM-3 is an important LFA-1 ligand that functions in the initiation of the immune/inflammatory response and also plays a role in chemotaxis.
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.